By Mike Bills, MS PT
There are so many definitions of “swelling”. In its simplest form, the term “swelling” is used to describe the response a tissue exhibits when it is injured, irritated or under undue and abnormal levels of stress. For example your body can experience swelling of basically three types:
- Swelling related to an injury: This would be the equivalent of twisting your ankle and then it is swollen for a while afterwards.
- Swelling related to irritation: This could be a muscle that is swollen because it is irritated or overworked. It could also be an organ, lets say your liver that is overworked or irritated because of some bacteria. Swelling that collects in your legs and feet due to poor circulation or a blood pressure problem is really the result of irritation to your heart and circulatory system not working properly and thus, not circulating the fluid in your body appropriately.
- Swelling related to abnormal stress: Think of this as being swelling that occurs because of overuse. An example of this would be lifting a box that’s too heavy for you causing some swelling in your back or leg muscles. Painting a room in your house could cause some swelling in your elbow or other parts of your arm.
True of False: All swelling is always observable and easily seen? THIS IS FALSE! In most cases most swelling is not seen. Yes, you will see puffiness or an enlarged area when it has been injured but most typically swelling is not visible. It is hidden inside the injured or irritated muscle or joint; it is collected in empty spaces in and around the area. True, when you sprain your ankle or fall and twist your wrist, you will see observable swelling but it is not common to see swelling in all of the other cases where swelling is present.
So what is swelling and why does it occur?
Swelling is the collection of fluid, think of it as water, in and around the tissue that has been injured, irritated or overworked. Your body has a certain amount of fluid that carries chemicals and enzymes in it that at times can fight off infection, bring nutrients and other things needed to facilitate healing, and more. This fluid is circulating throughout your body on a regular basis. When the self-protective mechanisms in your body perceive that something is wrong in the area (whether something truly is wrong or not), it will deliver a high dose of this fluid to the area. This rush of fluid to the area is what is really termed swelling.
There are many times where swelling is good. For example, this of when you twist your ankle after stepping off the curb incorrectly. The injury is perceived as a non-optimal event and the body will quickly deliver a lot of fluid to that area. In this case, the fluid is delivered to that ankle to do a number of things: provide increased support to the area and bring nutrients like oxygen and other things necessary to begin a healing process. In short, when an area is swollen, it will feel tight, sore, weak and experience varying levels of pain. This is good for the initial stages of whatever is causing the swelling: injury, irritation, overuse, because it acts as a warning sign to us that something is not optimal.
But it’s important to remember that swelling is only good for a few things and for a very short period of time. Swelling basically prevents healing from occurring because it continues to cause the sensation of pain. It also causes tissue in the area around the injury to be tight making it difficult for them to work properly and it makes it harder for the area to prevent future injury or repetitive injury. This is true for the basic reason that swelling restricts the blood flow to the area. Any area that is under stress or has experienced an injury needs an increase in blood flow to help with healing, loosen tissue to allow for normal mechanics and movement and most of all, deliver oxygen and other nutrients to not only facilitate healing but to strengthen the area and prevent weakness which leads to future re-injury.
Two types of swelling:
Acute: By definition ‘acute’ means it just happened. Acute swelling is swelling that just started in the past 12 hours or so. This was the body’s response to something and therefore the body performed its initial response. The acute swelling will cause some discomfort, tightness, etc. BUT THIS SHOULD ONLY LAST UP TO 12 HOURS. A perfect example of this is when your muscles are sore the next day after doing anything like running, gardening, shoveling snow, etc. This standard soreness or even pain is due to a “swelling” of the muscles that you overworked or overused, potentially irritated and even injured. BUT THIS SWELLING SHOULD BE GONE 12 – 24 HOURS LATER.
Chronic: Chronic means it is lasting longer than it should or reoccurring. Chronic swelling would be the swelling that occurred in the example above but was still present either to some degree or all of it 12 – 24 hours later. The injury, irritation, overuse was so great that the tissue could not get itself back in working order and thus the swelling stayed there. This is when swelling becomes a problem
As mentioned above, acute swelling is actually an okay thing. But when it lasts longer than 12 – 24 hours, it becomes an issue because it is preventing healing and causing continued pain. When fluid and swelling stick around beyond this time frame, they delay or even prevent healing from ultimately occurring.
Here are two examples of swelling at work:
1. Think about doing a lot of gardening or cleaning around the house one day. That night or the next day, your back, legs or arms are sore. Yes, those areas are actually swollen. That is a big cause of why they are painful. The swelling in those muscles and joints is pushing on nerves, causing things to be tight etc. This is the “check engine light” going off in your body. While you don’t actually see any swelling, your know that it’s there.
In this example one of two things can occur: Over the next 24 hours, your body does what it is supposed to do and the swelling begins to decrease and go away. Your body followed its normal protocol and found a way to increase blood flow to the area. This did a lot of things but first and foremost, it delivered oxygen and other nutrients, loosened tissue, and carried the swelling away to redistribute it throughout the body again. This is why your pain is gone within 24 hours of when it started.
But here is what very commonly happens after this muscle and joint soreness sets in: 24 hours later, the pain, soreness and stiffness have not decreased or may have even gotten worse. This is because your body didn’t do what it was designed to do. It didn’t increase blood flow to that area mostly because the swelling cut off blood flow. As a result of the decrease in blood flow and the continued presence of swelling, the pain, tightness, etc. all remain and may actually have increased. You can see how you switched from acute to chronic swelling there.
2. The second example would be that of a joint that is sore or painful and irritated. Ultimately, the soreness and pain is coming from swelling. Again, you most likely don’t see the swelling but what is happening is that the tissue in the joint is larger and thicker than it normally is. Most likely, this is due to overuse of the joint (you ran to much, climbing stairs, etc). The swelling that is there is pressing on nerves and causing pain, making the area tight and stiff, and ultimately preventing normal activity. All of this prevents good blood flow through the joint and thus the symptoms continue.
When should I worry about swelling:
- If you can visibly see any swelling then there is a problem. This swelling will not go away in 12 – 24 hours. The significant amount of fluid that is there will definitely prohibit the body from starting its healing process
- If you have had pain, soreness, stiffness in any part of your body for more than 24 hours the swelling is now chronic and needs expert attention.
- If you have had recurring bouts of pain, soreness, stiffness this is chronic inflammation at work and showing that the body is not healing itself on its own.
