Possible causes of hair loss include:
1. Androgenetic alopecia
Androgenetic alopecia is the medical term for male or female pattern baldness. Hereditary alopecia is another name for this condition. It is a common cause of hair loss.
Androgenetic alopecia is genetic. Males with this condition tend to lose hair from the temples and crown of the head. In females with androgenetic alopecia, the hair usually becomes thinner all over the head.
The condition is more likely to occur as a person ages, but it can start at any point after puberty. Many females who experience androgenetic alopecia develop it after menopause. Hormones may play a role in this.
It is possible to treat androgenetic alopecia with minoxidil (Rogaine, Loniten), a medication for hair growth. It typically takes about 6–12 months for hair growth to noticeably improve with this treatment.
Other potential treatments include:
- finasteride (Propecia), a medication that treats male pattern baldness
- spironolactone (Aldactone), a medication that may reduce female pattern baldness
- laser therapy, which applies a low-level laser to the scalp to stimulate hair growth
- platelet-rich plasma, in which a doctor injects plasma from a person’s blood into their scalp
- hair transplant, in which a surgeon transplants healthy hair follicles from one area of the scalp to another
- certain nutritional supplements
Some people may experience excessive hair loss shortly after giving birth. This is due to a decrease in estrogen levels. This type of hair loss is a temporary condition and usually resolves within a year or sooner.
A person may be able to increase hair volume by:
- using products for fine hair
- choosing a volumizing shampoo and conditioner
- avoiding intensive conditioners or conditioning shampoos, which may be too heavy for fine hair
- applying conditioner to the ends of the hair rather than the scalp to avoid weighing hair down
3. Telogen effluvium
Healthy hair follicles go through four phases of growth.
The hair follicle pushes out hair and causes it to grow during the anagen phase. Hair growth slows during the catagen phase, and natural hair shedding begins in the telogen phase, increasing in the exogen phase.
Telogen effluvium is a condition in which the hair remains in the telogen phase of the cycle. This causes more hair than usual to fall out, sometimes in handfuls.
Some possible causes of telogen effluvium include:
Telogen effluvium is usually a temporary condition that resolves over time, but it is advisable for people to contact a doctor to determine the cause. A doctor may need to treat the underlying cause of the condition to reduce hair loss.
If a doctor suspects a medication is causing hair loss, they may prescribe a lower dose or switch medications.
4. Anagen effluvium
Anagen effluvium causes large amounts of hair to rapidly fall out during the anagen (growth) phase of the hair cycle. It may cause hair to fall out from the head, as well as from other parts of the body, including the eyebrows and eyelashes.
Possible causes of anagen effluvium include:
Treatment for this condition depends on the cause but may include a topical solution of minoxidil (Rogaine).
If a person has anagen effluvium due to undergoing chemotherapy, cooling the scalp during the procedure may help. Hair will often grow back within 3–6 months after stopping chemotherapy.
5. Alopecia areata
Alopecia areata is an autoimmune condition that causes hair to fall out suddenly. The immune system attacks hair follicles, along with other healthy parts of the body.
Hair from the scalp, as well as eyebrows and eyelashes, may fall out in small chunks.
If a person has this condition, they should contact a doctor. A doctor may recommend corticosteroid injections to the scalp or prescribe other medication to help the hair grow back.
6. Traction alopecia
Traction alopecia is hair loss due to pulling hair into tight hairstyles, which causes it to break and come loose. Hairstyles associated with this condition include:
- tight buns or ponytails
If traction alopecia continues, a person may develop patches of hair loss and thinning of the hair.
Avoiding tight hairstyles will usually prevent further damage.
Certain medications have side effects that can cause hair to fall out.
Examples of such medications include certain types of:
If a person thinks that hair loss may be due to a medication, they can consult a doctor for an assessment. The doctor might reduce the dosage or switch the person to a different medication.
8. Birth control pills
People may experience hair loss while using birth control pills. Others might experience hair loss several weeks or months after they stop taking birth control pills.
If someone is taking birth control pills, they can choose a type that has a low androgen index. This may help lower the risk of hair loss.
Examples of birth control pills with a lower androgen index include:
Ovral and Loestrin have a higher androgen index.
Other forms of birth control that affect the hormones, such as implants and skin patches, may also cause hair loss.
The American Hair Loss Association recommends that people who have an increased risk of genetic hair loss opt for a nonhormonal type of birth control.
9. Nutritional deficiencies
Nutritional deficiencies can cause hair to fall out. Extreme diets that are too low in protein or certain vitamins, such as iron, can sometimes cause excessive hair shedding.
A person should contact a doctor for a blood test to check whether they have a nutritional deficiency that could be causing their hair to fall out.
A doctor may recommend dietary changes and supplements to treat a nutritional deficiency.
Ringworm is a fungal infection that can cause hair loss. Tinea capitis is the medical term for ringworm on the scalp, which can cause temporary patches of hair loss on the head.
Possible symptoms include:
- scaly and discolored ring-like patches on the scalp or skin
- patches of hair loss that start small and get bigger over time
- oozing blisters
- brittle hair that breaks easily
If ringworm does not heal by itself, a doctor may prescribe an antifungal medication such as griseofulvin.
Below are some frequently asked questions about hair loss.
What are the main causes of hair loss?
Male and female pattern baldness are the main cause of hair loss. However, lifestyle factors, such as frequent tight hairstyles, and medical conditions, such as alopecia, can also cause hair loss.
Why might someone suddenly lose so much hair?
Certain conditions, including anagen effluvium and alopecia areata, can cause hair to fall out suddenly. People should speak with a doctor to identify the cause of sudden hair loss.
How does someone stop hair from falling out?
The following lifestyle changes may help to prevent hair loss:
- reduce stress, such as through meditation or massage
- eat a balanced diet
- avoid tight hairstyles
- limit hair styling products that use heat, such as curling irons
- brush the hair gently
What vitamin deficiency causes hair loss?
Other vitamins and minerals may also play a role in hair loss. People can speak with a healthcare professional to determine whether they have a vitamin deficiency that may be causing hair loss.