Thyroid Problems and Their Impact on Hair Growth

Thyroid Problems and Their Impact on Hair Growth

• February 11, 2026
• Dr Paul Spano

Last updated on February 19, 2026

Some of the most talked about causes of hair loss include genetics and stress, but thyroid disorders can also lead to hair loss and changes in hair growth. The thyroid gland regulates hormones that influence how hair follicles grow, rest and shed.

When thyroid levels fall outside the normal range, the hair growth cycle can slow or become disrupted. Over time, this can lead to noticeable thinning across the scalp, increased shedding and slower regrowth, even in people who have never experienced hair loss before.

Understanding the relationship between thyroid function and hair growth helps explain why hair changes often accompany thyroid disorders. It also highlights why accurate diagnosis and appropriate medical care are essential when hair loss persists.

Here’s some insight into how thyroid problems affect hair growth, what thyroid hair loss looks like, the symptoms to watch for and the steps that can support recovery once thyroid levels are stabilised.

The role of the thyroid in hair growth

The thyroid gland produces hormones that regulate metabolism, energy use and cell turnover. Hair follicles rely on this hormonal balance to function normally. Each follicle follows a predictable cycle of growth, rest, shedding and regrowth.

When thyroid hormone levels are outside the normal range, this cycle can become disrupted. Follicles may enter the resting phase too early or remain there longer than expected. Over time, this leads to increased shedding and reduced regrowth.

Both underactive thyroid (hypothyroidism) and overactive thyroid (hyperthyroidism) conditions can interfere with hair growth. This explains why people often ask whether thyroid can cause hair loss. The answer is yes, particularly when hormone levels remain abnormal for extended periods.

Can thyroid cause hair loss?

Thyroid-related hair loss usually develops gradually rather than suddenly. It often appears several months after hormone levels become imbalanced, which can make the connection harder to recognise.

Hair loss associated with thyroid problems tends to be diffuse. Instead of forming patches, thinning occurs across the scalp. Some people notice a widening part, reduced volume, or more hair collecting in the shower or on pillows.

In more advanced cases, eyebrows and body hair may also become thinner. This pattern reflects the systemic nature of thyroid disorders rather than damage to individual follicles.

Importantly, thyroid hair loss does not usually result in permanent follicle destruction. With appropriate medical management and time, regrowth is often possible.

What does thyroid hair loss look like?

People often ask, “What does thyroid hair loss look like?” because it can resemble other forms of diffuse thinning. Typical features include:

• Even thinning across the scalp rather than a receding hairline or bald patches
• Increased daily shedding, especially when washing or brushing
• Hair that feels finer, drier, or more brittle
• Slower regrowth and reduced overall density

The scalp usually appears healthy, without redness, scaling, or scarring. This helps distinguish thyroid hair loss from inflammatory scalp conditions.

Because these changes overlap with other causes of hair thinning, proper assessment is essential before attributing hair loss to thyroid issues alone.

Thyroid hair loss symptoms beyond shedding

Hair changes rarely occur in isolation. Thyroid hair loss symptoms often appear alongside other physical signs that reflect altered hormone levels.

Common symptoms associated with thyroid dysfunction include fatigue, changes in weight, sensitivity to temperature, dry skin and alterations in heart rate. Some people also notice changes in mood or concentration.

When hair loss occurs alongside these broader symptoms, it strengthens the case for thyroid evaluation. However, some individuals experience hair changes as one of the earliest signs, before other symptoms become obvious.

Why thyroid imbalance disrupts the hair cycle

Hair follicles are highly sensitive to hormonal shifts. Thyroid hormones influence how long follicles stay in the active growth phase. When hormone levels fall outside the optimal range, follicles may prematurely enter the resting phase.

Several months later, shedding increases. This delayed response often causes confusion, as the trigger may no longer feel relevant by the time hair loss becomes noticeable.

In prolonged or untreated cases, follicles can remain inactive for longer periods, resulting in visible thinning. Restoring hormonal balance helps follicles gradually return to normal cycling, but this process takes time.

How thyroid-related hair loss is diagnosed

Diagnosing thyroid-related hair loss begins with a thorough medical assessment. Blood tests are used to measure thyroid hormone levels and assess whether the gland is underactive or overactive.

A detailed hair and scalp examination helps rule out other causes of shedding. Factors such as family history, recent illness, stress, nutritional status and hormonal changes are also considered.

Because hair loss can have multiple contributing factors, identifying thyroid involvement early helps guide appropriate management and avoid unnecessary treatments.

Can thyroid hair loss grow back?

One of the most common questions is whether thyroid hair loss can grow back. In many cases, the answer is yes. Hair follicles are usually not permanently damaged by thyroid imbalance alone.

Once thyroid levels are stabilised under medical care, shedding often slows over several months. Regrowth typically follows, although it may take six to twelve months to notice meaningful improvement.

Hair texture and density may take longer to fully recover. Patience is important, as hair growth follows its own timeline even after hormone levels normalise.

Supporting hair recovery after thyroid stabilisation

While thyroid management addresses the underlying cause, additional support can help optimise scalp and follicle health during recovery.

Medical hair assessments may identify reduced density or prolonged resting phases that benefit from targeted therapies. Options such as Growth Factor Treatment or Regenera stem cell treatment may be considered in suitable cases to support follicle activity.

These approaches aim to improve the scalp environment and encourage healthier growth patterns. They are typically used alongside medical care rather than as a replacement for thyroid management.

When hair loss persists despite thyroid control

In some individuals, hair thinning continues even after thyroid levels stabilise. This may occur when other forms of hair loss coexist, such as genetic pattern thinning or long-standing follicle miniaturisation.

A comprehensive evaluation helps determine whether additional treatment options are appropriate. Early intervention often provides more predictable outcomes than delayed care.

Understanding the full picture ensures that hair restoration plans are realistic, tailored and medically appropriate.

The importance of early assessment

Hair loss related to thyroid problems is often reversible, but timing matters. Early assessment by your doctor or hair loss clinic allows for accurate diagnosis, prompt treatment and better long-term outcomes.

If you notice ongoing shedding, diffuse thinning, or changes in hair quality alongside general health symptoms, medical review is recommended. A structured approach ensures both thyroid health and hair concerns are addressed with care and experience.

FAQs

How do I know if my thyroid is causing hair loss?

Thyroid-related hair loss usually presents as diffuse thinning across the scalp rather than patches. It often occurs alongside symptoms such as fatigue, weight changes, or temperature sensitivity. Blood tests are required to confirm thyroid involvement. A medical hair assessment helps rule out other causes and ensures the most appropriate care.

Can thyroid hair loss grow back?

In many cases, thyroid hair loss can improve once hormone levels are stabilised. Hair regrowth takes time, often several months, as follicles return to a normal growth cycle. Additional hair loss treatments may be recommended to support recovery where appropriate.

Can thyroid cause hair loss without other symptoms?

Yes, hair loss can sometimes appear before other thyroid symptoms become noticeable. This delayed or isolated presentation makes diagnosis more challenging. Blood testing and clinical assessment are essential to confirm the cause. Early review allows for timely management and better outcomes.

Can medical treatments help speed up hair regrowth from thyroid problems?

Once thyroid levels are managed, supportive therapies may help improve scalp health and follicle activity. Options such as Growth Factor Treatment or exosomes stem cell treatment may be considered where clinically appropriate. These are discussed during consultation based on individual assessment.