The words Acute and Chronic are used as very rough descriptions of which phase of healing an injury is currently in.
Basically, acute is early, and chronic is later. Often, a middle stage is included: sub-acute.
Here goes the simplest explanations I could write:
Acute: first two to three days after an injury. This is the stage in which inflammation is most apparent, visible swelling, and often the most sensitive pain. This is when you can barely move an injury (if its bad enough) without it hurting. However, as long as its not a bone fracture, moving early (respecting your pain, not pushing it) is often recommended.
Sub-acute: first two to three weeks. Healing is well underway. Swelling is going down, but it can still hurt quite a bit. This is where people are like “I don’t understand! why isn’t this better yet?!”, frustration sets in… but don’t fret my pet… relax. In this phase it’s usually a good idea to get moving as much as you can. You should even be starting some safe, simple strengthening exercises within your pain free range of motion.
Chronic: From the second or third week onward until healing is complete. The tissues that have come together in the earlier stages are now beginning to strengthen up. It shouldn’t hurt as much anymore. How long this takes can vary widely, 6 months to a year… Sounds long, but within this time you are usually strong enough to do most things, as long as you don’t do anything stupid. Be realistic, and progress yourself back step by step.
You may notice from these stages that healing usually takes weeks to months depending on the severity. This explains why people often hurt themselves, take a couple days off, return to their sport, and feel the same injury again. In these cases, you didn’t necessarily “re-injure” yourself… you’re not done healing in the first place!
Now… these timelines are obviously very rough approximations of the true stage of healing you may be in. Generally, more severe injuries involve longer phases. Some very small bumps, bruises and scrapes will heal completely in a couple weeks. A bone break takes much longer, and so will more severe sprains and strains.
Your health care provider will make a good guess as to where you’re at in terms of healing based on many details: what you hurt, how it happened, and what are the signs and symptoms. All this information comes together to form a unique clinical picture. As you can imagine, the possibilities are endless.
Therefore, don’t try and figure out these things yourself. I believe you should always get checked by a professional.
But, I also believe in the value of patient education.
Knowing more about what happened to you can help you make the best decisions about your recovery. You are the most important person in your journey back to health, so get reading. A good start is the injuries section of this site. I try to write about tricks and tips to help get you back to what you love as fast as possible. Learn as much as you can!
I hope you found this information useful.