The body was designed to heal itself. Healing begins on a cellular level, continuing up to the skin through layers of tendons, ligaments, and muscle. Since healing begins on such a basic level, it takes time for each level to become stronger. Here is how it works...
Let's say you were running and you fell on a trail with good-sized stones, sticks, and other bits of nature. Your left knee hit first and hardest. You're bleeding through the sticks, stones, and dirt. As you stand to assess the damage, your knee is already swelled and you feel you can't walk on it.
The body sends messages of pain and healing via the nervous system to the brain. The body then begins the process of healing itself. First, the body sends blood to the wound. It clots and then scabs over, preventing more dirt and debris from causing an infection.
Timing: This occurs within seconds.
Now the immune system leaps into action. Bacteria is carried away from the wound. White blood cells appear to help the wound heal. A whitish fluid helps to further clean the wound. Having done its thing, the immune system goes back home. The wound will be swollen, red, and tender.
At this point, your doctor will tell you to put ice on the injury to help with swelling. If you're near a store with, or you're lucky enough to have, three foot high and 50 pound capacity hoshizaki ice machines, you'll have a constant supply of ice. Keeping the injured knee elevated will also be an instruction from your doctor.
Timing: This part of the healing process takes two to five days to accomplish.
With the cleaning completed, the body now repairs ruptured blood vessels and growing new tissue. Collagen is produced inside red blood cells, making a waffle-type pattern with other collagen strands. These form the basis of new tissue. The skin will draw together, eventually healing over. The scab will fall off.
Timing: This will happen within three to six weeks.
It should be noted here that scar tissue is not the same as normal skin. It doesn't grow hair or sweat. It takes time for the scar tissue to heal completely and become as strong as regular skin.
Timing: Three months to a few years.
If the wound doesn't receive enough blood full of nutrients and oxygen, then healing will take longer. Those fighting diabetes, obesity, vascular or heart problems, and seniors will have wounds taking longer to heal. Stress causing high blood pressure, tobacco use, drinking, and some types of medication also keep wounds from healing in good time.
Tendons and ligaments act as springs or shock absorbers around joints or where two bones meet. They can be pulled, stretched, ruptured, and strained. The same swelling, redness, and pain happen as it does with other types of wounds. The healing process is much the same, with a couple of twists. Keep the ice handy.
The first stages of healing explained above get into gear. By the time the collagen reaches the wound, it doesn't form a waffle-like tissue. It wraps around the tendon or ligament with a jelly-like appearance. The cells more or less delete the wounded tendon or ligament, forming a new one in its place. It will take time to become as strong as the original.
Timing: Healing time will take one year.
Returning to work or playing a sport before the complete healing of a wound means putting pressure on the wound. That takes longer for the wound to heal, and you could re-injure yourself. Most doctors will advise you to sit it out and let the body heal itself. Then you can return to your job or sport at 100 percent.