Your hair has a growth cycle that consists of three parts: regeneration, degeneration, and a rest cycle. At times, however, this cycle can be disrupted causing your hair to cease its growth. Many factors can contribute to stopping hair growth in humans, however most are not cause for medical concern. For more information on increasing your hair growth, speak to your doctor or a licensed dermatologist.
According to the Mayo Clinic website, your hormones can both promote hair growth or hair loss. Your hormones also help regulate your hair growth cycle and how long each stage takes to complete. As the website suggests, the growth phase of scalp hair, known as anagen, typically lasts two to three years. Hormonal irregularities can cause this phase to last longer in some people, however, which can lead to less hair growth overall.
As the Mayo Clinic also states on its website, a medical condition known as alopecia areata can also cause your hair to stop growing. This condition can also cause you to lose hair from your scalp. While the cause of this disease is unknown, scientists believe that some people are genetically predisposed to develop alopecia areata. A family history of the disease can also put you at higher risk for the disorder. You will lose hair if afflicted with alopecia areata, however most people tend to regain hair growth after several years.
According to the UAB Health System website, high levels of stress can also cause your hair growth to stop. Physical and emotional stress can also cause you to lose your hair. The medical condition telogen effluvium can develop as a consequence of severe mental stress, such as the loss of a loved one. This physical and mental stress can interrupt your hair's normal growth cycle, which normally grows in 2-5 year cycles. Hormonal imbalances, viruses, or physical trauma can also trigger this condition. Telogen effluvium usually resolves on its own and does not require any treatment, as the UAB website suggests.