Hair follicles go through three recurring stages: regeneration, degeneration and rest. For hair to grow, the hair follicles' stem cells must be given and respond to the signal to divide, which starts the process. During the regeneration process, the hair follicle descends through the dermis and outward, where it can be seen by the human eye. During this period, hair continues to grow until the second stage, degeneration. However, for some people, their hair will not grow.
Stress, whether physical or emotional, is one of the causes of lack of hair growth (Experimental Dermatology, Peters & Platz, 2006). Hair also ceases to grow on a stressed person because the body goes into survival mode (American Hair Loss Council, 2009). While in survival mode, the emphasis is on mending and maintaining fundamental bodily structures, rather than hair growth.
Another cause of hair not growing includes certain medications, such as for gout. Read the inserts of all prescribed and over-the-counter medications for any possible side effects, such as stoppage of hair growth. Understand that hair growth may not resume while on the medication, but when off the medication may possibly resume.
Hormonal causes such as menopause could affect hair growth. For example, with the onset of menopause, often the thyroid malfunctions. The thyroid regulates other bodily functions, such as hormones. When hormones are affected, other bodily functions could be affected, such as hair growth.
Nutrition could affect hair growth. If a person does not consume an adequate amount of vitamin-rich foods, such as vegetables, there will be an impact on the hair growth cycle. Simply put, for hair to grow, cells must have the proper nutrients to thrive.
New hair cells originate underneath the scalp rather than at the base, as originally thought (Journal of Cell Science, 1990). Because of this newfound knowledge, researchers and companies can better devise ways to treat the lack of hair growth and baldness.