Hair loss, also called alopecia, can start at almost any age as you enter adulthood.

You can start losing your hair as early as your late teens and early 20s. But you might have a full head of hair with almost no thinning or balding until well into your 50s and 60s.

There’s a lot of variation from person to person. But the general consensus around balding is that the older you get, the more likely you’ll see signs of balding.

Let’s get into the most noticeable signs of balding, how to tell the difference between natural balding and other causes of hair loss, and what you can do about it if you need treatment for a condition that causes hair loss.

There are various methods that medical professionals use to diagnose patterns of balding.

Balding in a characteristic pattern is known as androgenetic alopecia. It’s thought to be caused by genes passed down in families that make you more or less likely to go bald. It’s the most common cause of balding in women.

The two most well-known categorizations for hair loss in men and women are the Hamilton-Norwood classification system for men and the Ludwig system for women.

Signs of balding in men

Balding is assessed using the Hamilton-Norwood classification system. This system focuses on recognizing two possible major patterns of hair loss that can be seen:

Temples

Hair starts thinning around the temples and at the top of the back of your head, which is called the crown or vertex.

Receding hairline

Hair starts thinning and moving back around the front of the head on the sides, often called a receding hairline.

Here are some of the other signs of balding in men you might notice:

Top of the head

Thinning hair on the top of your head can happen over time. You won’t go bald overnight — you’ll probably start to notice thinning especially at the top of your head for many years before baldness becomes fully visible.

One of the most common types of thinning in men is the receding hairline, which makes an M shape as the two sides recede at a faster rate than the middle of the scalp.

Signs of balding in women

Balding in women can begin anywhere between the ages of 12 and 40, or even later.

Signs of baldness in women are classified using the Ludwig system. This system has identified two major types of balding:

Thinning on top

You might notice thinning across the entire top of the head and not on the sides.

Widening part

Widening of the part on the top of the head is also a common sign of balding in women.

Here are some other signs of balding in women to look out for:

Thinning across the whole head

This is the most common type of balding pattern in women, as opposed to the receding M-shaped hairline in men.

These causes of hair loss are different from androgenic alopecia, and can occur in both men and women. Some types of alopecia can happen as a result of genetics, physical injury, or an underlying condition that can cause the hair to thin or create bald spots. They include:

  • Alopecia areata. This is a small, circular area of sudden hair loss that appears without any symptoms. The beard and eyebrows can also be affected in addition to other hair on the body.
  • Telogen effluvium. This type of hair loss is reversible and occurs as the result of a stressful event, like a hospitalization, and sometimes from a new medication.
  • Tinea capitis. Tinea capitis, a fungal infection on the scalp, can cause small localized scaly spots on the scalp that may also have pustules. This can result in permanent scarring hair loss.
  • Cicatricial alopecia. This is a general term referring to hair loss that creates permanent scarring. The hair follicles left behind are destroyed and scar tissue forms rather than grow more hair. This term refers to several conditions that permanently damage hair follicles.
  • Nutritional deficiency. If your body is lacking a sufficient amount of protein or iron, among other vitamins, it can result in hair loss. However, a true vitamin deficiency is very rare.
  • Thyroid conditions. A problem with your thyroid is a well-known cause of hair loss. Doctors often recommend checking this if you have hair loss that appears to have no underlying cause.

Once hair loss occurs, it’s difficult to regrow the lost hair. However, there are a few options to prevent further hair loss and slow down the thinning process, including:

  • Minoxidil (Rogaine). This is an over-the-counter (OTC) medication that can be rubbed onto the scalp regularly to help prevent more hair loss.
  • Spironolactone (Aldactone). This medication for women may be prescribed for off-label use. It works by binding to receptors for androgen hormones in your body, keeping androgens like testosterone in check to prevent hormone imbalances.
  • Topical retinoids. Some dermatologists recommend special compounded hair topicals that include a small amount of topical retinoid, which may be helpful.
  • Hair transplant. This procedure involves your hair that’s harvested from one area and transplanted to the bald regions.
  • Laser light therapy. Low power light therapy and lasers are used to increase the density of your scalp hair.
  • Prescription medications. Certain medications can be used to treat androgenic alopecia related hair loss. Finasteride (on-label for male pattern baldness) and dutasteride (off-label) are two examples.
  • Platelet-rich plasma. This involves a process of using a person’s own blood, which is processed into platelet-rich plasma, and then injected into the scalp to stimulate hair growth.

See a doctor if your hair loss or baldness pattern is accompanied by any other painful or uncomfortable symptoms, including:

  • swelling around the areas of baldness
  • excessive itchiness or scaling around balding areas
  • burning, stinging, or pus discharge around balding areas
  • sudden hair loss on other parts of your body
  • excessive hair growth on other parts of your body
  • sudden changes in weight, including weight loss or weight gain
  • have recently had a high fever (over 101°F, or 38°C)
  • have complications from a recent surgery

Balding is totally natural as you get older. And there’s plenty you can do to your hair to keep it looking the way you want it, even as you lose hair.

But if you notice sudden hair loss after a major event in your life or along with other unusual symptoms, see your doctor to diagnose and treat any underlying causes of hair loss.