# Healing
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**Healing** is happens naturally after a physical [[injury]] to the tissue or [[bone repair|bone]]. Special care must be taken for open [[wounds]], which are prone to infection.
![[stages of healing.png]]
The first stage of healing is [[coagulation|hemostasis]], or the stopping of blood loss. This happens first through **vasoconstriction**, which tightens the vessels and reduces the blood flow through them. [[Platelets]] are drawn to the damaged area and release clotting factors to begin [[coagulation]] (or "clotting"), which turns the blood from a liquid to a gel. The platelets also allow the production of **fibrin** with makes a clot, which binds to any collagen in the surrounding tissue and pulls the edges of the wound together.
[[Inflammation]] begins 5-10 minutes after the injury, bringing with it an influx of [[white blood cells|leukocytes]] and [[platelets]], as well as allowing damaged cell debris and toxins to be carried away. It is in this stage that a blood clot becomes a scab.
The **proliferation**, sometimes called the **granulation** phase is when the real meaty work of healing takes place. [[fibroblast|Fibroblasts]] make [[collagen]] and other components for the [[extracellular matrix|ECM]], new blood vessels are created in a process called **angiogenesis**, and the edges of a wide or deep wound are pulled closer together.
The **remodeling**, sometimes called the **maturation** phase of healing [[collagen]] is oriented properly and the cells that have finished their duty undergo [[apoptosis]].
> [!health]- Healing Timeline
The stages of healing are not really distinct phases, but continuous and overlapping.
> ![[healing timeline.png]]
## Factors that Affect Healing
There are many factors that affect healing in different ways.
- The specific disease processes/type of wound**
- Location of the wound
- The more vascular the area, the easier it is for nutrients to get in and waste products to get out from the cells.
- Nutritional status
- Wounds in particular need a lot of [[protein]] to heal.
- Age -- the old and the young
- Infection will make healing harder
- [[diabetes mellitus]] patients are at a high risk for wounds not healing or becoming infected
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