How Long Does Hair Typically Grow?
Hair length is completely controlled by the length of the anagen phase of your hair follicle. How long this period lasts is generally determined by genetics, but can also be affected by hormones, and even extreme stress. More specifically, there is a chemical signal that ultimately controls the exact growth cycle.
Following the anagen phase is the catagen phase. It isn’t yet known what triggers the catagen phase, but once it is triggered, the outer part of the root ends up being cut off from its nutrient supply (blood), as well as the cells that produce new hair, thus your hair stops growing. This phase lasts about three weeks.
Next up comes the telogen phase where the follicle is in a resting state and your hair is now a “club hair”, completely dead down to the root. During this stage, these hairs are relatively easy to pull out (as can happen while brushing/combing/washing your hair), but if they manage to last long enough, they’ll eventually be pushed out by a new hair as the cycle begins again.
At any given time about 85%-90% of your hair is in the anagen phase, 1-2% is in the catagen phase, and 10-14% is in the telogen phase. However, extreme stress can trigger the anagen phase to stop prematurely and hair can rapidly progress to the telogen phase, even as much as 70% of the hair on your body. When this happens, the majority of your hair that should still be growing can fall out all at once.
For the hair on your head, the average length of the anagen phase is about 2-7 years. However, in extreme cases which are quite rare, some people have anagen periods for their heads as small as most people’s anagen phases for the hair on their arms and legs which is about 30-45 days. For these people, their hair never naturally grows more than a few inches long. The opposite is also true, with people whose anagen phase can last decades for their scalp hair. Both of these extremes are very rare though. Most people can expect about a half inch of growth each month. If your hair grows at this rate, you can expect a maximum hair length of 12 to 42 inches.
Factors Affecting Hair Growth
You can't change genetics, which set upper and lower parameters for hair growth, but a number of other factors can affect hair growth.
Scalp health: Infections dryness, and frequent irritation of the scalp can slow hair growth.
Hair follicle health: If your hair follicles are damaged, your hair will stop growing sooner and may not grow at all. Frequent hair-pulling can damage hair follicles.
Hair breakage and hair shaft health: With the exception of the area immediately surrounding the follicle, hair is made of dead cells. That means that a better diet, hair vitamins, and other factors won't improve the overall health of your visible hair. They'll only alter the hair follicle, potentially improving growth. But an unhealthy hair shaft can still affect hair growth for one simple reason: damaged hair tends to break off more easily.
Physical health: Your physiological health can affect the health of your hair follicles. A healthy diet rich in vitamins and nutrients improves follicle health, while nutritional deficits can slow hair growth.
Season: Hair tends to grow more quickly in warm, humid climates. Cold weather also dries out the hair shaft, making it break more easily. Remember: breakage makes hair look as if it's growing more slowly than it is.
How can you prevent damaged hair or split ends?
Wondering how to get rid of split ends? When the hair strand is split or fractured, the only solution to restore a healthy fibre is a visit to your hair stylist for a trim with the Split-Ender PRO.
The Split-Ender safely cuts split-ends and damaged hair in just minutes. The new Surgy-Trim™ System Technology safely trims away split-ends, dry and damaged hair while preserving your beautiful, long and healthy hair.
You can find the Spit-Ender range of products here.