Why swelling happens when we are injured and how we can effectively reduce swelling

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Why swelling happens when we are injured and how we can effectively reduce swelling

Pain and swelling are our body’s natural reaction to trauma. Insect bites, allergic reactions, injuries, illnesses and anything in between can trigger different levels of pain and swelling in different kinds of people. 

Depending on the underlying cause, swelling can happen anywhere from our internal organs, muscles, tissues or skin.   

In the case of injuries, swelling and pain are the first steps toward the healing process. However, they can delay recovery if they last for too long, hence, understanding what happens to your body when you’re injured and learning how to help your body recover faster are keys to effective minor injury management. 

Find out how you can heal faster by performing these tried and tested methods. 

What happens when you’re injured?

An injury disrupts how normal cells function. When you hit or bump your leg, the cells’ protective membranes become damaged and die, interrupting the supply of oxygenated blood to the tissues. Without this, the body fails to adequately produce adenosine triphosphate (ATP), the cells’ energy-carrying molecules, and one that is essential for recovery.   

The body’s healing process initiates as soon as you’ve injured yourself, and the healing process can be categorized into these stages.  

Phase 1: Bleeding or bruising 

Approximately within four to six hours following a trauma, blood and fluids rush to the affected area as your body’s way of protecting itself. This manifests in external bleeding if you cut your skin or have an open wound. Muscles have abundant blood supply, so they bleed more, or produce a large bruise, and for a longer period of time after they’ve been forcefully impacted by something.

Phase 2: Inflammation  

Almost immediately after a trauma, our body starts forming blood clots in the injured area, resulting in acute inflammationThe body likewise releases chemicals to push the blood platelets to stick to the exposed parts of the tissues and create a plug in an attempt to stop the bleeding.   

As white blood cells rush to the injured site, fluids from the blood vessels leak into the surrounding tissues, producing the early and obvious signs of inflammation: swelling, redness and warmth. 

It is also at this stage where the body’s cells send pain signals to the brain. Towards the end of this initial inflammatory stage, specialized protective cells called monocytes work to clean up the dead cells and other unwanted matters at the injury site.  

Phase 3: Reparation

Blood platelets release chemicals that facilitate long-term injury healing during this phase. As the cells begin the reparative process, they create an extracellular barrier that mixes with high collagen levels, forming scar tissue.  

The process of creating scar tissues for injury reparation starts within the first two days and can last for several weeks or months.  

Phase 4: Strength and flexibility training

Consider the fact that your injured muscles and tissues may not be as strong as they were prior to the injury, and perhaps they will never be the same again (it’s sad, I know). 

The best you can do is to condition your body by performing stretches and exercises and to seek physical therapy, if needed, that is aimed at restoring functional strength.  

It is at this stage where you have to be very careful, because while the muscles and tissues around the affected site should be groomed with strength training, the same area may, on the other hand, be easily re-injured. 

Depending on the location and severity of the injury, this process may last for several weeks or months. 

Why does swelling happen after a trauma?

Swelling happens due to fluid buildup and may either be oedema, referred to as a swelling in the tissue outside of the joint, or effusion, an in-joint tissue swelling (i.e swollen knee, hip, or ankle). In some cases where ligament injuries are involved, both blood buildup and in-joint swelling may occur, leading to a symptom called hemarthrosis. 

How long does swelling last after an injury? 

Swelling is unavoidable in cases of traumatic injuries. As you may already know or experienced yourself, where there’s swelling, there’s pain, too. As such, the injured area will be its most painful within 24–48 hours after the injury.  

Bruising will form in the next few hours following trauma and become more visible the next day, making the area appear purple or black. This is called acute swelling, and it happens within the first 24 hours of an injury. 

In some cases, swelling may become chronic and last for weeks. If you’ve had swelling from an injury for more than three weeks, consider going to the doctor.   

Why can swelling be a bad thing?

Swelling may be considered as a first step to the healing process. Heat, redness and swelling are signs of inflammatory response and are clear signals that your body is working to repair itself. 

A rush of blood to the affected area results in redness and heat, while increased movement of fluids and white blood cells to the injured site causes swelling. Nerve compression and the release of various chemicals, meanwhile, trigger pain and discomfort. 

Pain and swelling means you won’t be able to use the injured body part so that you are less likely to re-injure it. While this may be good news, swelling becomes bad news if it lasts too long. Why? Because the lack of activity may lead to muscle atrophy and reduce your ability to activate the muscles. Chronic swelling also makes tissues tough and less pliable, making it more susceptible to re-injury.

5 methods to Help Reduce Swelling From an Injury 

So, if I were you, you’d want to avoid swelling as soon as possible by doing the following:

1. Protect 

It is important to protect the affected site or nearby tissues from further injuries. 

How to do it: Depending on the location of your injury, supportive devices such as slings, splints, crutches, canes or walking sticks can be used to do the job. 

2. Rest

Sports buffs and athletes may be tempted to continue with their activities following an injury, or even to tough it out through pain. However, experts advise against performing any activity that may cause pain and further aggravate your condition. In general, using an injured area contributes to swelling by encouraging blood flow and propagating damaged cells. 

How to do it: Active rest may be better instead of not moving at all. This entails  performing simple stretches or non-weight bearing exercises, such as walking or biking. 

3. Ice or cold therapy

Applying cold therapy immediately after an injury and up to 48 hours thereafter can help reduce pain and swelling. 

Cryotherapy slows down the receptors that send pain signals to the brain, creating an analgesic effect. Ice also helps control the swelling by narrowing blood vessels to reduce the bleeding, the flow of fluids and cellular metabolism.   

Reusable and instant ice packs, ice baths, ice cubes and other cooling tools may be used to deliver these benefits to an injured area.  

How to do it: Applying ice packs is pretty straightforward. Freeze or chill an ice pack in the freezer or fridge for at least two hours and then apply it on the affected site. If you’re using ice pucks or ice cubes, cover the ice with a thin cloth before putting it on the affected area to prevent getting ice burn or frostbite. Be mindful of the time, too, and do not place the ice on your skin for more than 20 minutes. 

Make sure you don’t have any sensory and circulatory issues before your ice application. 

Cooling your leg area may pose a challenge, as most ice packs are too small to cover even half of your leg. However, there is this leg ice pack for fuss-free cooling and immediate pain relief from leg injuries. This amazing product covers and hugs your leg completely, starting from the thigh and going down the knee and shins. Whoever says it’s hard to treat leg injuries or post-op pain should try this consumer-approved and FDA-registered leg ice pack.

4. Compression

Wrapping the injured area with an elastic bandage serves a more important purpose than just keeping an ice pack in place.  

Compression, or applying adequate pressure, decreases swelling and helps facilitate faster healing by keeping unwanted fluids away from the injured area. 

How to do it: Adequate compression means that the bandage wrap is not too tight nor too loose. You’ll know that the bandage is too tight when you feel numbness, tingling, increased pain and swelling below the bandage. Loosen the bandage if this happens. 

Otherwise, use these multi-purpose ice packs that come with elastic bandages to maximize the benefits of cold therapy, even in your joint areas. 

5. Elevation

Keeping the injured area above the heart will reduce blood flow and lessen the swelling. Even when your leg is injured, it is important to keep it elevated so blood and other fluids do not pool around the injury, leading to pain, a potential blood clot and delayed recovery. 

How to do it: Use pillows to prop up your legs as you lie or sit down. 

Do medications reduce swelling?

Non-steroidal anti-inflammatory drugs (NSAIDs) help reduce inflammation and alleviate pain. Ibuprofen and naproxen are the most commonly used medicines to relieve pain and swelling.    

Reminder: Follow the instructions and dosage guidelines carefully to avoid potential side effects. 

3 things to avoid when you have a soft tissue injury

For the first four days following a soft tissue injury, avoid the following:

  1. Heat application: This opens up the vessels, promoting blood flow. It should not be applied to an injured area as it could worsen swelling.
  2. Alcohol: Not only does alcohol disrupt your immune system, but it also increases blood flow and inflammation and further delays the healing process.
  3. Massage: While a massage is great overall, it should be avoided in the first few days for the same reasons mentioned earlier. 


Swelling is the body’s natural response to injury, and it could last for a few days for minor injuries. Performing the self-care methods discussed in this article helps hasten injury recovery and avoids chronic swelling that hinders your healing time.  

Hi, I’m Steve Stretton, owner and manager at Gelpacks.com. What do you think about our suggested methods? Do you have anything to add to our list? Tell us more about it in the comments section or write to us here.

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