Finding hair in your brush is normal: We shed. But if a person starts losing an unusual amount of hair, it can be cause for concern.

Losing hair normally doesn’t have much effect on your appearance or warmth, as your head has plenty more to make up for the daily loss. But there may be a more significant reason for your hair loss when you start seeing your scalp or bald spots.

When you think of hair loss, you may think of the genetic factors, such as male pattern baldness. Hormones, thyroid problems, and other diseases can all cause hair loss too.

So, what are these various causes, and how do you know if they’re to blame for your excessive shedding?

Women may lose hair following childbirth or while in menopause. Women who have hormonal imbalances can have hair loss.

Aside from genetic male pattern baldness, men can lose hair as their hormonal composition changes with age. Hair loss is caused by your follicles’ response to the hormone dihydrotestosterone (DHT).

Perhaps one of the most common hormone-related causes for hair loss is a thyroid problem. Both too much thyroid hormone (hyperthyroidism) and too little (hypothyroidism) can lead to hair loss. Treating the thyroid disorder can often reverse the hair loss.

Physical and psychological stress can cause hair loss. Surgery, high fevers, and blood loss can cause enough stress to result in excessive shedding. Childbirth can result in hair loss for several months after delivery.

As for psychological stress, the link is less well-defined. However, many people have reported losing hair at times of extreme mental stress or anxiety. And hair loss for other reasons can still be stressful.

The causes of physical stress are often temporary, and the hair loss subsides as the body heals.

You can combat mental stress with lifestyle changes, such as:

DID YOU KNOW?The American Academy of Dermatology (AAD) estimates that we shed about 50 to 100 hairs each day.

Pharmaceuticals can come with a long list of side effects, including hair loss. Chemotherapy is the most well-known cause, but others include:

These medications affect people differently and may not cause hair loss in everyone. Learn more about the medications that can cause hair loss.

Zinc and iron deficiency are the most common nutritional links to hair loss. But some evidence indicates that low intakes of the following vitamins and nutrients could also be to blame:

Lupus is an autoimmune disease that can cause hair loss. Generally, the hair loss is patchy and accompanied by lesions on the scalp.

Some lupus medications also may lead to hair loss.

Many other medical conditions can lead to abnormal balding, including:

Skin conditions such as psoriasis and dermatitis can occur on the scalp and interfere with hair growth. Infections such as ringworm of the scalp and folliculitis can also cause hair loss.

The search for causes and potential treatments by people experiencing hair loss is understandable. Research has tied hair loss to lower self-esteem, body image issues, and increased anxiety. The Journal of the American Academy of Dermatology recommends assessing for anxiety and stress when diagnosing hair loss.

Many of these nongenetic causes for hair loss can be successfully treated, and the hair loss averted and even reversed.

Talk with your doctor about your concerns and the potential causes for your hair loss. They can recommend a treatment that’s right for you.