Wendy Wisner

Published on July 31, 2023

 Medically reviewed by 

Susan Bard, MD

EKATERINA DEMIDOVA / GETTY IMAGES

Typically, hair grows an average of about half an inch each month.1 This means hair grows about 1/8 of an inch each week, and you can expect your hair to grow one-and-a-half inches in three months.

At any given time, the hair on your body is in different phases of growth. The majority of your hair is actively growing while some of your hair is in a resting, non-growing phase, and some of your hair is naturally being lost. Hair grows for about six years before it falls out, and it’s normal to lose about 100 hairs each day.12

 9 Tips for Hair Regrowth

Phases of Hair Growth

Most humans have an average of two to five million hair follicles. 100,000 of these follicles are located on the head, and the rest are distributed on the arms, legs, face, chest, and elsewhere.3

Caucasians with light hair generally have higher hair density than Caucasians with darker hair, meaning they have more hair follicles per square inch. Caucasians in general tend to have higher hair density than people of African or Asian descent.3

At any given time, your hair is in various stages of growth. The four stages of hair growth are:34

• Anagen phase: When your hair is actively growing; about 90% of your hair is in this phase.

• Catagen phase (regression phase): When your hair slows in growth and becomes detached from the shrinking follicle; 10% or less of your hair is in this phase.

• Telogen phase (resting phase): When your hair is neither growing nor shedding; 5-10% of hair is in this phase

• Exogen phase (shedding phase): When your hair naturally falls out of the follicle.

In your lifetime, each individual follicle will go through this cycle about 10-30 times. The anagen phase (growth phase) lasts between two and eight years, which means this is how long a hair will continue to grow on your head. However, growth in other areas of the body may be shorter. For example, the growth phase for eyebrow hair is only two to three months.5

The rate at which hair grows and is lost can vary based on factors such as your age, medical conditions, and how you care for your hair. Healthy, young hair usually grows about half an inch each month, and is lost at a rate of about 100 hairs a day.16

 18 Causes of Hair Loss—And What You Can Do About It

What Can Affect Hair Growth?

Many factors can affect hair growth and how fast your hair grows. Your hair growth may speed up at times and slow down at other times. Sometimes hair growth slows down substantially, or hair is lost and not replaced. Although hair loss or slowed hair growth is not life threatening, it can affect your self-esteem, mental health, and quality of life.4

Medical Conditions

Certain health conditions can cause hair growth to slow, hair to thin, or hair to fall out faster. Sometimes hair growth stops altogether. Medical conditions that affect hair growth include:6

• Alopecia areata, which causes bald patches on the face and scalp and may cause eyelashes and eyebrow hairs to fall out

• Anemia, or a low level of red blood cells

• Bacterial infections

• Some autoimmune conditions, such as lupus

• Some infectious diseases, such as syphilis

• Radiation therapy or chemotherapy for cancer

• Ringworm on your scalp

Hormones

Your hormones can have a strong effect on your hair growth and on hair loss. For example, the hormones during pregnancy can slow down hair loss, leading to a fuller head of hair. After giving birth, your hormones will adjust back to normal and can cause an increase of hair loss as the extra hair falls out naturally.6

Other hormonal conditions that can affect hair growth include:5

• Thyroid conditions, like hypothyroidism and hyperthyroidism, both of which can cause hair loss

• Decreased estrogen, such as during menopause, which can cause thinning hair

• Increased levels of dihydrotestosterone (DHT), which is a contributing factor for male pattern hair loss

Stress and Illness

Experiencing periods of significant stress and trauma or going through a serious illness can increase hair loss. You may start to lose clumps of hair in the weeks after the stressful event. This can appear as large amounts of hair that collects when you brush or wash your hair.6

This type of hair loss is usually temporary, and your normal hair growth pattern should resume in a few months.6

Aging

Aging can have significant effects on your hair. Not only does hair tend to thin and become grayer as we age, but it tends to fall out faster and grow slower.7

Male pattern baldness and female pattern baldness are hormone-related conditions, but they are also age-dependent.8

Hair loss from male pattern baldness usually begins around the age of 30 and can sometimes result in complete baldness by the age of 60.7

Female pattern baldness typically reduces the density of hair and can start to reveal some of the scalp. It usually starts to appear between the ages of 30 and 50.87

 How Is Alopecia Diagnosed?

How to Speed Up Hair Growth

If you are dealing with hair thinning, slow growth, or hair loss, you may be looking for ways to remedy this. Options for speeding up hair growth include:9

• Changing your hair styling routine, which may include refraining from wearing your hair in a tight ponytail, bun, or cornrows, and wearing hair extensions for long periods

• Changing your hair care routine, including using fewer hair products and doing fewer treatments like perms and hair coloring

• Considering using Minoxidil (Rogaine), which is widely known as an effective treatment for hair loss; give yourself 6-12 months to see results, and use the treatment daily

• Trying microneedling, which can be used alongside Minoxidil for optimal hair growth

• Trying red light therapy, a treatment with minimal side effects that might be more expensive and may require several sessions

• Trying platelet-rich plasma (PRP); this procedure injects your own plasma (retrieved from a blood sample) into the area with hair loss

• Asking your healthcare provider about whether any vitamins or supplements may be helpful

• Asking your provider for prescription hair growth treatments, such as Finasteride (Propecia) or Spironolactone

When to See a Healthcare Provider

Hair growth issues aren’t a problem on their own, but sometimes they point to an underlying medical condition. It’s important to connect with a healthcare provider if you are noticing significant changes in hair growth or are losing noticeably more hair.

You should see a healthcare provider if you:6

• Are losing hair in patches

• Are aged in your teens or twenties and losing large amounts of hair

• Are experiencing itching, pain, or signs of infection

• Are experiencing symptoms like weight gain, exhaustion, muscle weakness or sensitivity to cold temperatures

When diagnosing a health issue related to hair loss, the healthcare provider will typically ask about your medical history and examine your hair and scalp. They may run blood tests to diagnose any underlying medical conditions, and possibly request a biopsy of your scalp tissue to determine the cause of your hair loss.6

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A Quick Review

Hair grows at about half an inch per month, and the hair on your head usually grows for about six years before falling out. Your hair is in a constant state of growth and renewal, and it’s normal to shed hair each day, even as new hair grows.

Factors that affect hair growth include stress, illness, various medical conditions, and aging. Remedies for hair loss or slowed growth may include changing your hair-care routines or products, trying topical treatments like Minoxidil, or asking your healthcare provider about prescription medications for hair loss.

Most causes of slowed hair growth or hair loss are not serious, but you should always contact a medical professional if you have any questions about your hair or want any help with hair growth.