What Are the Causes of Sudden Hair Loss?

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Men and women can experience sudden hair loss that may seem to come out of nowhere. While sudden hair loss is often not that severe or life-threatening, it can still be frustrating, especially if you're losing your hair in a prominent place like the top of your head. Sometimes called alopecia, sudden hair loss can be highly emotionally distressing and cause worry.

There are many reasons why you might suddenly lose a lot of hair. Hair loss can be genetic or arise due to hormonal changes, nutritional deficiencies, or general stress. This article looks into the causes of sudden hair loss and what you can do to stop it.

What Causes Hair Loss?

Sudden hair loss can be a confusing and unsettling experience. Although several conditions cause temporary hair loss, telogen effluvium and alopecia areata have the most significant impact on the general population because they account for the majority of individuals who experience hair loss.

Telogen Effluvium:

Telogen effluvium (TE) is the most common and widespread hair loss condition. TE is caused by a disturbance of the hair growth cycle and is triggered by a significant physical, chemical, or psychological stressor. The resulting hair loss typically occurs over a three- to four-month period, but it can take up to six months for the hair to start to grow back.

The cause of TE remains unknown, but it is believed that the stressor causes the hair follicles to go into the telogen (resting) phase faster than expected. This means that a “shock” to the system can cause a person to lose a large amount of hair in a short period.

Hair loss due to TE can be brought on by a wide range of things, including:

  • Fever
  • Major surgery
  • Pregnancy
  • Major illness or infection
  • Severe emotional or psychological stress
  • Surgery or trauma to the area of the scalp where the hair is falling out
  • Childbirth
  • Changes in antidepressants
  • Metal Poisoning
  • Dermatological conditions
  • Stressful personal relationships
  • Drug reaction

Alopecia Areata:

Alopecia areata is another form of sudden hair loss that an autoimmune response is thought to be brought on. This means that the body's immune system attacks the hair follicles themselves. AA is not contagious, but it also does not have a specific cause.

Two forms of AA that are the most common:

  • Alopecia Totalis — This is a condition where a person loses all the hair on the head.
  • Alopecia Universalis — This is a condition where a person loses all the hair from the scalp as well as from the eyebrows, eyelashes, and sometimes from other areas of the body that have hair.

The hair loss caused by AA usually occurs in patches and can take up to five years to grow back.

What Else Can Cause Rapid Hair Loss?

Several other conditions can cause sudden or rapid hair loss, including:

Iron Deficiency:

An iron deficiency in the body can be caused by long-term blood loss, malabsorption issues, or excessive bleeding due to an underlying condition.


Some medications can also cause hair loss, especially if taken for an extended period. For example, birth control pills can cause female-pattern baldness, while chemotherapy drugs are known to cause hair loss in both men and women.

Hormonal Imbalance:

An imbalance in the body's hormone levels can also cause hair loss. For example, a condition called polycystic ovarian syndrome is a condition where a woman's reproductive organs produce more male hormones than average. This, in turn, can cause the hair on the head to thin out over time.

In addition, a condition called Cushing's syndrome can also cause hair loss. This occurs when the body has too much of the hormone cortisol, which causes the hair on the head to thin out.

Improper Hair Care:

Prolonged exposure to harsh chemicals, such as bleach, dyes, and other chemicals, can cause the hair on the scalp to become damaged over time. If these chemicals are used too frequently or are misused, they can cause permanent hair damage.

Brittle or Dry Hair:

Brittle hair is hair that is prone to breakage. This type of hair can be caused by a number of issues, including coloring it too often, using chemicals on it, or using styling tools on it too often.

Thinning Hair:

Thinning hair is hair that is prone to breakage because it has become too weak to support its own weight. This type of hair can be caused by the same issues that cause brittle hair. Hair can also be thinned out by wearing tight hairstyles too often.

Damaged Hair:

Damaged hair is hair that is prone to breakage because it has been damaged by something. This can include any of the issues that cause brittle or thinning hair.

Hair Loss Solutions

The most effective way to treat hair loss is by visiting your primary care doctor, who can provide you with advice tailored to your health.

Two of the most effective ways to stop hair loss are Minoxidil or Finasteride. Either one of these treatments may help you control your hair loss and regain lost hair, as well as confidence.

Minoxidil is a topical treatment, which you apply directly to the scalp. It has been approved by the FDA and has been proven to increase hair growth after only 12 months of use, and the benefits continue to improve the longer you use it. It is the only treatment that has been proven to regrow lost hair and has been used for over 30 years to treat hair loss.

Finasteride is a pill that you take orally. It is a proven treatment that has been shown to stop further hair loss and promote hair re-growth. It also prevents male-pattern baldness from worsening by halting the conversion of testosterone to dihydrotestosterone (DHT), which is responsible for hair loss. It works by blocking the enzyme responsible for the conversion of testosterone to DHT, known as 5-alpha-reductase.

Both Minoxidil and Finasteride are FDA-approved treatments, which are safe to use for treating hair loss. They are practical and can be used together to double the benefits. 

Minoxidil and Finasteride work well together and can be used either as stand-alone treatments or as an effective double-action treatment.

You can get both treatments online through Phoenix by scheduling an appointment to virtually see one of our physicians, who will advise you on the best treatments for your hair loss.

Start your hair-loss screening online today.

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This blog post is for educational purposes only and does not constitute medical or other professional advice. Your specific circumstances should be discussed with a healthcare provider. All statements of opinion represent the writers' judgement at the time of publication and are subject to change. Phoenix and its affiliates provide no express or implied endorsements of third parties or their advice, opinions, information, products, or services.

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