Age: Almost everyone will notice hair loss and hair thinning as they age. Our cells continually grow and die off at all ages, but when we’re older, our cells die off more quickly than they regenerate. It’s why we get weaker bones and thinner skin. And it’s a similar process for our hair. 

Genetics: The most common type of hair loss, androgenetic alopecia, is hereditary and related to age. It’s commonly referred to as male or female pattern hair loss, and it affects more than 50 million men and 30 million women in Africa. This is a more extreme form of hair loss that usually begins in young adulthood and gradually progresses with age. 

Hormonal changes: People with conditions like polycystic ovary syndrome (PCOS) and congenital adrenal hyperplasia (CAH) have higher androgen levels, which can cause female pattern hair loss

Nutritional deficiencies: A chronic form of telogen effluvium can occur. This type of hair shedding starts slower and lasts longer (over 6 months). Possible causes are often related to nutritional deficiencies. Having low levels of iron, vitamin D, and zinc have all been shown to be linked to hair loss. 

Autoimmune disease: Alopecia areata is a form of hair loss that is autoimmune. The body’s immune system attacks healthy hair follicles, causing them to fall out. 

Chemotherapy and radiation: Hair loss can be a very real fear for many patients who have received a diagnosis of cancer and need to undergo chemotherapy or radiation. Cancers are due to cells that grow too quickly. Chemotherapy drugs are often used to kill off these cells, so they don’t form tumors or spread. However, because cells in your hair follicles also grow quickly, chemotherapy can affect your hair, too. 

Infections: Infections can affect the scalp and cause hair to fall out. This happens when bacteria, yeast, or fungi overgrow and invade hair follicles. You might see pus bumps, redness, and scaling. The scalp can feel itchy or even painful. If you notice any of these symptoms, see your dermatologist right away.