Bathmate Hydromax Swelling
When we evaluated the Bathmate, we covered all of the penis pumps that are part of the Hydro series, which includes the Hydro, Hydromax, and Hydroextreme models. We offer in-depth testing and analysis. Bathmate Hydromax Swelling
With more than one million satisfied customers, a customer satisfaction rate of 95 percent and a unique technique that can increase the size of your penis by an average of 2-3 inches up to 5,
Bathmate’s penis pumps that are vacuum-filled have an impressive presence on the market for products for male enhancement.
It could be treatment for erectile disfunction or Peyronie’s Disease, rehabilitation following prostate surgeries, an astronomical growth in the length of the penis and size, as well as enhanced sexual pleasure, erectile disorder (ED) or Peyronie’s disease (Peyronie’s), and enhanced sexual pleasure: erectile augmentation
Everything you must know about Bathmate Hydropumps can be found in this article.SHOP BATHMATE
Bathmate Review: What is Bathmate Penis Pump?
These are the four main components you should know:
1.) The Tube where you are expected to place your penis.
2) The Comfort Ring It is placed at the bottom of male genitals (without any testicles). The reason for the name is due to the ability to press the Bathmate deeply into your body, which blocks air from entering and leads to the creation of the formation of a vacuum. You will not be able to expand its size or its circumference if your seal is incorrect.
3) The Pump. When you press the penis against your pelvic seat, the water is expelled as you relax your grip, the penis gets “pumped” by creating a vacuum pressure. The penis is made of an elastic skin that is able to withstand repeated use. You are in complete control thanks to the ability to squeeze lightly or firmly.
4) The Latch Valve. It allows you to alter the pressure. It is able to be closed and opened by using only one hand due to its ergonomic design.
How Does a Bathmate Hydropump Work?
If the tub is filled up with water from the Bath or Shower, the water pushes out the air through the tube’s interior. tube.
After inserting your penis in the tube, you then place your Bathmate firmly against your body near the base of your penis while securing it in the tube.
Because the comfort ring is pressed against your body, it is impossible for any air to enter and create an air vacuum.
When you take water out of your tube, an natural reaction creates a vacuum pressure that causes it to suck in blood to your penis.
This draws blood into your penis, which counteracts the shift in pressure in the tube.
This puts little pressure on your heart. The reason for an erection is an increase in the flow of blood around the penis. Its duration depends on how sexually stimulated a person is.
The erection may last for as long as half an hour. If you are looking to increase in the length of your penis, you will need to exercise regularly.
Increases to the length of the penis require a regimen similar to how muscle growth occurs.
Bathmate suggests using your hydropump every day for at least 4 to 6 months for a total of 15 minutes which is broken down into three intervals of five minutes per session (a total of 3 x 5 minute usages).
As your penis gets larger, you will need to replace your previous Bathmate with one which is one size bigger.
This is like to how you would raise the weight of the dumbbells that you use to lift weights.
How Do I Use a Bathmate Hydropump?
Whichever penile pump from the Bathmate Hydropump product line–the Hydro7, the HydroMax or the HydroExtreme that you select as the one that will help you achieve your objectives efficiently The method by which you apply each product to your penis is very similar.
1.) Give yourself five minute to immerse yourself in warm water to soften the skin on your scrotum and penis.
This can reduce the chance that your testicles are drawn into the device. When you are ready to utilize the Bathmate gadget, ensure that your testicles are away from the tube by drawing them back with your hand that isn’t being used to position the device.
Although there isn’t any risk of injury in this situation however, it will be uncomfortable.
2.) When you’re at the bathroom, hold your Bathmate upside down until it’s being sprayed by water, but make sure the black hole at the device’s top is closed.
You do not need to secure the clasp of your Bathmate when you plan to use to bathe in it. all you have to do is immerse the gadget in the water.
3.) Place your sagging penis in the tube and press your Bathmate tightly on your pubic bone to make sure the tube is securely sealed.
The Bathmate penis pump is angled either upwards or downwards, depending on which is more comfortable for the user.
4) To begin pumping to begin, remove the cap with the black color from the device’s bottom and then, open the cap.
Each time you pump, it will trigger brief bursts of water to escape.
You will feel your penis being drawn into the chamber. You will be able to notice stretch of the skin on your front.
Due to the change in pressure the blood vessels within the penile region will start to expand and lead to the formation of an intimate erection.
Because of the way water distorts your vision the circumference of your penis will look like it has increased.
5) Before removing your penis from the tube, remove the quick-release valve by pulling the valve cap upwards to release the vacuum.
This must be done prior to taking your penis out of the tube. If your Bathmate isn’t inserted securely enough in the pubic bone to secure your device properly, pumping when you shower may be more difficult because air can get in and decrease suction.
This can happen in the event that the device isn’t sealed properly.
Pumping should begin when the black cap at the end of the device is removed.
If you do not the water will pour out of your Bathmate Hydropump. If you find that air is stuck between the comfort ring as well as the pump could find that removing the comfort ring prior to filling it and replacing it when pumping is easier.
Higher pressure is possible through shorter, more efficient pumps, whereas lower pressure can be achieved using slow pumps.
It is recommended to remove the vacuum, then refill the machine, and then begin pumping two or three times throughout an hour-long session.
This will enable you to achieve the most significant gains possible through every workout.SHOP BATHMATE
Are Bathmate Hydropumps Safe To Use?
If they are correctly used and the directions given from the company are followed, the Bathmate vacuum pumps do not produce any adverse side effects and are completely non-invasive.
Penis extenders are an alternative to the traditional penis pumps. Penis injuries can happen but one of the most frequent causes is excessive pumping of the genitalia.
When performed too frequently or over a prolonged duration, excessive pumping or misuse can cause injury to the tissuethat could result in weaker sexual erections.
“Men will over-pump,” says Dr. Christopher Fox, a senior lecturer in sexual health at the University of Sydney.
This is why there is a chance of injury to the vascular system of the penis.
It is highly recommended that the procedure be performed with the guidance of the therapist for sex who is knowledgeable of what they are doing or another pumper who has previous expertise with the procedure.
The recommendation of experienced users is to make sure that the water is warm. apply pressure to the penis in order to relax muscles prior to starting the workout, and start with a beginner program that runs between five and ten minutes per day, and then gradually progress to sessions that last for twenty minutes.
There is a loophole to this rule in the case of taking warfarin, or any other kind of anticoagulant that thins blood, or have any kind of health condition that affects the way your blood is clots.
Which are the circumstances under which the usage of Bathmate Hydropumps or another type of penile pump is considered safe?
Fluid retention is one of the negative effects that is often associated with the use of the penile pump which is water-based.
It occurs when the suction that has drawn blood flow to the penis is also drawing in fluid. This means that the penis is at its maximum capacity.
In the course of this the skin that covers the penis becomes swollen, and the penis’s circumference increases.
This does not have any effect on the growth of the penis, but it could induce an appearance of a doughnut on the bottom of your penile’s glans.
After twenty-four hours, this should go disappear, but it will depend on the amount of fluid retention you have. Based on the suggestions made by Bathmate, the most effective method for avoiding fluid retention is to break up longer sessions lasting between 15 and 20 minutes into shorter sessions of 4-5 mins.
Which is Better, Bathmate Hydropumps or Traditional Air Pumps?
Short answer Short answer: Bathmate Hydropumps.
The inherent benefits of warm water, which makes the penis’s tissues more pliable and further improves the flow of blood through vascular dilation, are utilized in Bathmate pumps in order to increase their efficiency.
The effects of warmth are conditioned on nerves, which stops the discomfort that occurs when stretching the muscles, something users of standard air vacuum pumps commonly experience.
This effect can be replicated by applying an un-warmed towel to one’s penis for a few minutes prior to using a traditional pump.
If you do, however, use the pump before the game the time you spend on preparation means longer time away from playing.
It’s obvious which of the two options–having the feature built into the routine of pumping or adding an additional step will provide you with the greater level of convenience.
If air pumps are used, lubrication is required to maintain the penis ‘ suppleness when stretching; however, this requirement can be avoided by using water.
Water is denser than air and provides a more equal dispersion across the penis as a result of this property.
The bruising process is among the negative effects of air pumps, and it’s due to parts of the penis having excess pressure due to an uneven distribution of air.
This might result in bleeding beneath the skin as well as tiny red spots on your penis. A gauge that shows the pressure at the moment is normally present on conventional pumps.
If you exceed the maximum pressure there’s no way to release the pressure, and the air will continue to expand inside the tube, regardless of the way to let it out.
It is your responsibility to determine how much pressure is sufficient pressure and to make sure it isn’t exceeded.
Are you aware of what the ideal air pressure level is for a specific scenario?
In the event that you pump too quickly or forcefully the one-finger valve in Bathmate Hydropumps will release the pressure.
You can pump to maximize profits with no risk of injury due to the design of the Bathmate that stops water from entering the tube and, consequently, pressure right from the start.SHOP BATHMATE
What are Bathmate Penis Pumps Used For?
According to the findings of a poll that was conducted in 2020 by Bathmate the results showed that 70 percent of respondents experienced an increase in size.
Premature ejaculation. The effect of numbing can be obtained by using a Bathmate Hydropump for five to ten minutes immediately prior to engaging in sexual activities.
This can help the session to go on for longer. You can also avoid premature ejaculation by training your penis to remain upright for longer times without the prospect of sexual release.
This is another method for stopping premature ejaculation. Even if your penis may be pressuring your Bathmate and you aren’t capable of obtaining relief from pumping your legs unless you get it removed first.
Harder erections. In the same survey conducted in 2020 by Bathmate, 76% of respondents reported having more powerful erections.
Furthermore you can achieve this by utilizing the pump prior to engaging in sexual activities while wearing the penis band.
After you have removed your Bathmate, the bandage will stop the blood taken into the penis from escaping as rapidly.
It will help keep your erection in an extended period of time, while preparing you for your future partner.
It is essential to keep in mind that the ring needs to fit snugly against the body in order for the erection to be maintained This can cause discomfort for some men.
Stimulation of sexual organs and foreplay. When you get an erection you might feel intense excitement, and when you consistently get a strong erection, your desire for sexual encounters may increase.
Vacuum penis pumps cause erections when being used, but these devices also possess the potential to increase the number of natural erections, as well as greater intensity of orgasms.
Penis pumps produce a sucking feeling, which may be very delightful, and they can be used for masturbation as well as foreplay with edging, light control, and total domination.
They are incredibly multi-functional and versatile toys.
Although they weren’t intended to be used on body parts other than the ones you are using however, you are able to be imaginative using the pumps.
The pump can be utilized on the clitoris area, the Nipples, as well as any other erogenous areas without any danger.
Bathmate Penis Pumps Review For Erectile Dysfunction
Oral drugs or pharmaceuticals that are pushed via the tip of your penis into the tube within the penis, injections of shots into your penis, as well as surgically installed penile implants all could cause adverse reactions or fail to function or could be very risky.
Bathmate Hydropumps, when utilized appropriately, enhance the oxygenation of penile tissues, which aids in retaining penis length after an operation to remove the prostatectomy.
Additionally, they help to limit the likelihood of aberrant fibrous tissue growing within the penis.
This helps to preserve erectile function.
The men with erectile dysfunction who use penis pump vacuum can enjoy an uneasy erection, and also notice a significant increase in their sexual satisfaction.
The percentage of improvement ranges between 80-90 percent.
The usage of a Bathmate hydropump in treating the problem of erectile disfunction is, as compared to other treatment options, less expensive over the long term, and non-invasive and can be utilized alongside other medications.
Additionally, it may aid men in regaining their the erectile function after surgical procedures.
In treating erectile disfunction with the Bathmate Hydropump you have the option of applying it right away prior to engaging in sexual activity to stimulate the flow of blood and create an erection, or building your routine to ensure that you use it every day for a minimum of five days each week, and gradually progress to 20-minute sessions on a daily basis.
This will improve the quality of your natural erections and eliminate the need to resort to using Bathmate prior to engaging in sexual activity.
Penis Pumps & Prostate Health
Nerve damage and shrinkage of the penile are both common adverse effects of prostatectomy occurring in approximately 70% of patients and both of them get worse over time.
Studies conducted in clinical settings have shown that patients who utilize a vacuum penis pump are able to keep the size of their penis prior to surgery and recuperate sexual function faster after surgery.
The absence of natural erections may be the result of an injury to the nerve after surgery which may cause an insufficient amount of oxygen that is reaching those tissues in the penis. It could be that a deficiency in oxygen may result in the formation of fibrous tissue.
This could result, as a consequence of this, long-term erectile dysfunction.
Based on several research studies, medical professionals suggest using penis pumps during rehabilitation to help boost circulation of oxygen to the penis, and also to help maintain the tissues.
This can help to avoid this from happening. In a study conducted in 2011 13 men who underwent prostatectomy combined the use of a penis pump and tadalafil (20 mg three times a week and daily pump use five days weekly) and the results were compared to the 7 men who took 20 mg of tadalafil by itself.
The men in the control group had significantly less improvement in erectile dysfunction.
Those who used the penis pump received higher scores for penile hardness on the International Index of Erectile Function.
Furthermore, 92 percent the men in the penis pump group could achieve sexual intimacy to orgasm, while only 29 percent of men who were in the tadalafil only group could achieve it.
After surgery, another 42 men began using the penile pump on daily basis for a period of 90 days.
Only one man experienced a reduction in penile length of at the very least 0.4 inches.
In comparison to the typical 48 percent of men who suffer a significant reduction in the length of their peniles following prostatectomy and are not provided with rehabilitation using vacuum penis pumps, the percentage of patients who receive this procedure is much greater.
Penis pumps using an air vacuum showed a distinct and significant effect.SHOP BATHMATE
Bathmate Review For Peyronie’s Disease
Peyronie’s disease is a non-cancerous condition that causes the penis to develop fibrous scar tissue. This makes erections extremely painful and bent.
The reason for this is the development of Peyronie’s disease.
Peyronie’s disease may prevent a man from having sexual activity, induce erectile dysfunction, and shorten your penile shaft.
The pressure put on the penis with penis pumps that are vacuum-operated can cause plaque to degrade or be repaired. This eventually results in the penis curvature becoming straighter.
The efficacy of penis pumps that are vacuum-filled was examined throughout the course of a year during a study that involved 31 males who were diagnosed with the disease Peyronie’s.
The treatment resulted in significant improvement in the penis’ length, and the curvature of the penis also improved in 21 of the males.
Patients with Peyronie’s disease are advised to only use the penis pump when their condition has not changed in at least three months , and the curvature has not become extreme after two sessions per day for several months.
This is a crucial thing to remember.
Do Bathmate Penis Pumps Increase Penis Size?
As per Dr. Christopher Fox, “Men who use penile pumps recreationally report big gains in sizes. Of course, the size decreases if you don’t maintain the pump, but men who do report significant gains in sizes.”
According to the results of clinical research, patients who use penis pumps that are vacuum-filled for erectile dysfunction have high levels of overall satisfaction.
Bathmate offers an claim substantiation page on their website . It contains impartial reviews, results along with endorsements and before-and after videos of people with healthy penises. They claim to gain 30 percent the length of their penis and in girth after having used the product for six months.
According to a study that was conducted in 2020 among 12,000 customers of Bathmate, 81 percent claimed having more erections. 70.6% reported having longer erections after having used the product for two months.
When only the HydroXtreme was taken into consideration, 92.9 percent of users reported noticeably improved erections, and 80 percent experienced longer or better erections, or both.
Your penis will grow in length and circumference if you continue to use it regularly.
You will, however, require you to use your Bathmate in order for your gains to last.
If you don’t keep up the work then you’ll lose the effects, much as when you’re trying to build muscle in the gym.
There is no evidence to suggest that these devices bring about any meaningful long-term gain in terms of size, according to Professor Wylie who is a consultant in the field of sexual health. In a study that was published in 2011, entitled ” Non-invasive methods of penile lengthening: fact or fiction,” the researchers arrived at the conclusion that there was no evidence to back the notion that penis pumps result in permanent changes in size, even when they are not utilized continuously.
The size of the penile may be maintained over a longer period of time by men who use a penis pump three to five times a week for twenty minutes.
However, should they stop pumping for even a couple of days, their penis shrinks back at the same size as it did before they began pumping. However, if it is pumping your penis you will experience a momentary rise in size.
Through continued use the penis that is already large can not only be maintained , but can be substantially increased in size.
This is enough for some men, and when viewed in context, how is a regular 20-minute exercise any different from a skincare routine or a workout similar in length when the outcome is a considerable improvement in confidence at night?SHOP BATHMATE
Which Bathmate Hydropump is Best for Me?
The Bathmate Hydropump product line is available in various sizes. The one best suited to your needs will depend not only on the size of your current pump but also on the goals you want to accomplish with the vacuum penis pump.
If your natural penis size is a amount of inches or less when it’s in erect position and straight, the model of the product that’s best suited to you will be HydroMax3.HydroMax3 model of the product.
Other models with numbers include the HydroMax5 model as well as the HydroMax7 model.
If you’re planning to use the HydroMax5 penis, you’ll require penis that’s at least 4 inches tall; for the HydroMax7 it’s a penis that stands at least 7 inches tall; and so on. It is vital to choose the appropriate dimension for the Bathmate hydropump in order to get the best outcomes from it.
This enables a baseline to be established for future improvements; However, if your pump is not of the correct size, you might not get the right pressure, which could cause zero results, or results that are less appealing or even a negative experience.
How to Correctly Measure Your Penis Size
1) Measure yourself using your penis upright.
Penis length is determined from at the highest point of your penis which is the side that is facing your face when you gaze down on yourself.
It is not measured on the bottom of the penis, which is closer to the testicles.
2.) If you have excess pubic hair or fat pushed towards the side, take a measurement of how far your tailbone extends back up to the pubic bone.
3.) To determine girth by wrapping the tape measure around your shaft in the location where it’s most thick and take note of the place where the two tape ends meet.
To start, use the size calculator on Bathmate’s website to find the right pump for your measurements Simply enter your length and girth measurements in the units of measurement you prefer.
The Bathmate Hydropump Product Line
Bathmate provides Bathmate’s Hydro7 kit for first-time users, Bathmate also offers the HydroMax along with the HydroMax Wide Boy for experienced users and their HydroXtreme and HydroXtreme Wide Boy for experienced users who want to achieve the highest increase in size. All of the products are available through their web site.
Hydro7, formerly “Bathmate”
It was the first Hydropump from Bathmate that was released to the market in 2006 under the name “Bathmate Hercules.” Hydro7 revolutionized the market for penile pumps due to its water-based nature and cost less than half of the cost of its closest rival.
The Hydro7 is appropriate for those who have penises between 5 and 7 inches length when they’re upright and was designed to support the ordinary consumer beginning off.
There are three color options offered for the Hydro7 three colors: white, red and blue.
When ordered directly from the Bathmate website All of Bathmate’s hydropumps come with a 60-day refund policy during which there is no question asked, a 2-year warranty, and free shipping.
Because Bathmate has distribution centers all around the world Most orders will be delivered within 5 business days and all items are delivered in unremarkable packaging, that is not marked.
Bathmate HydroMax Series
The Hydromax line of vacuum penis pumps has been the extensively utilized penis pump in the world, and it has a satisfaction rating that is greater than that of 92 percent of customers who were interviewed.
The pump has more power than the Hydro7 pump, which makes it ideal for users seeking an increase in size that is gradual, but not overwhelming or have an initial sexual length that is more than 7 inches.
Bathmate HydroXtreme Series
The HydroXtreme series is designed for users with advanced skills who are trying to achieve maximum gains in size as swiftly as they can.
Bathmate’s Bathmate HydroXtreme penis pump has the handball as an additional part, which helps to maximize the pressure and gives 35 percent more suction than comparable pumps.
The HydroXtreme line by Bathmate has five different versions that come with a complimentary accessory pack.
If you’re looking for customers who’ve outgrown conventional vacuum penis pumps and require a more powerful penis pump, the HydroXtreme product line includes choices ranging in size from HydroXtreme5 and up until the HydroXtreme11.
HydroXtreme11 HydroXtreme11 is the biggest penis pump to ever been invented.
Cleaning Kit ($46.98). A set of accessories that will help ensure the longevity the pump.
This kit is essential even though it incurs an additional charge at the time of checkout.
This is because there is an opportunity for a high level of bacteria growth in warm water, and the pump needs to be maintained free of dirt to ensure that the rubber will remain malleable.
Cushion Rings ($14.98. Additional cushion rings can be added to the base of your pump prior to use, making the process of pressing the seal into the pubic bone more enjoyable and less painful.
The Capsule Travel Case ($46.98). A durable case that protects your pump from harm and ensure your privacy when you are on the road.SHOP BATHMATE
How to Get the Most Gains with Your Bathmate Hydropump
What is Jelqing?
Bathmate recommends the use of jelqing as a manual workout to be utilized alongside the Bathmate Hydropumps.
Jalqing is a tradition that dates back to the Middle East as a rite of passage dating back to the ancient Arabic civilizations. Jelqing is useful in warming up the penile tissues, stopping fluid retention, and training and preparing your penis in a safe way for the more intense pressures that are applied by the hydropump.
In addition to using your Bathmate Hydropump you should make jelqing an element of your daily routine.
1) Make sure that the penis is warmed up and flexible prior to expanding the flow of blood by applying warm water over the region.
This will allow the penis to expand more easily.
2.) Apply lube, and by using a firm grasp, encircle the base of the semi-erectcock.
Repeat this process many times. When you move this grip, you should only apply pressure in one direction, moving from the base until the tip. Additionally, you should not pull the skin back.
3.) It is imperative to never jelq an entire erection. Beginners should stop jelqing once their penis is fifty percent of an erection after performing one hundred fifty repetitions.
This number can be increased to seventy-five percent and finally to ninety percent. However, beginners should never jelq a full erection.
Build a Workout Routine With Your Bathmate’s Hydropump
It’s essential to keep pumping your pump if you’re hoping to gain penile growth and also keep those you have. Doing this will allow you to maintain the gains.
It involves forming a routine program of exercise that is adapted to your personal time limitations, goals, and the amount of effort you believe you can put into it.
Advocates of the Bathmate Hydropump with more experience categorize routines as “Newbie,” “Intermediate,” or “Advanced.”
Whether or not you have been using jelqing for a long time, your level is determined by how comfortable you are with Bathmate Hydropumps.
It is crucial not to overdo the exercise and to work your way up to more intense workouts using a penis pump that is vacuum; this is important in the same way that it is crucial not to do too much when you are building muscles.
You are able to experiment with the several Bathmate Hydropump routines offered in every level to see which will cause your penis to react most positively.
A good example of a simple routine for beginners might go something like this:
- Week 1 & 2: Pumping sessions of 5 to 10 minutes, 4 times every week.
- Week 3 & 4: Pumping sessions of 10-15 minutes 5 times every week.
- Week 5 and 6 5 and 6: Pumping sessions lasting between 15 and 20 mins, six times per week.
Make sure you get at least one day of relaxation every week is important and that you should not exceed six times.SHOP BATHMATE
Alternative Vacuum Penis Pumps to the Bathmate Hydropump
Bathmate Penis pump hydraulic, which is evident by its winning of its Venus award for best new product in 2014, and the prize for the most effective male enhancement equipment in 2012.
Penomet, much like Bathmate, is essentially a water-based vacuum pump that may be used in the shower, the bath, or even as a typical penis air pump.
The versatility of the pump makes it an ideal alternative.
Penomet makes use of the AquaPressure technology to deliver ideal vacuum pressure.
Penomet pumps can be adjusted made of polycarbonate plastics which the company claims are nearly unbreakable, and they make five different gaiters made of medical-grade silicone. Each has different suction strength.
When you buy a Penomet with all 5 gaiters You’ll be able to use the same pump from the first time you utilize it all the way through many years of enhancement and training in the future. Utilizing several models of Bathmate
As soon as your penis grows by a specified percentage, all additional gains you make will be limited to maintenance only till you can upgrade your model that is more space and a more powerful suction. It’s simpler to keep track of your progress in the areas of training, expansion or recovery when you are relying on just one model. Penomet products are available in various sizes, including those of the Force 60, 65, 70, and 75 as well as the Extreme Force 80 and X85 Monster Gaiter, the latter of which is the main rival to Bathmate’s HydroXtreme11.
More than 10 years of study and testing, it was found that the use of Penomet devices for six months, with six sessions per week led to up to a 20 percentage increase in the length, a thirty percent rise in thickness as well as an improvement on the quality overall of an sexual erection.
Penomet, similar to Bathmate offers a money back guarantee for the first sixty days and a warranty that is valid for three years. A two-year warranty is provided by Bathmate.
The initial investment is the biggest drawback of Penomet penis pumps in comparison to Bathmate Hydropumps.
Comparing it to the Bathmate HydroXtreme11, which retails for $399, Penomet Premium package, which comes with all gaiters from the basic gaiter up through the Extreme Force 80 gaiter, has a suggested retail price of $457. Bathmate Hydromax Swelling