How to tell hormonal hair loss from seasonal hair loss: key differences

Seasonal hair loss is a temporary response of the body (more common in spring or autumn) that resolves on its own within 1–2 months and does not lead to a noticeable reduction in hair density.

Hormonal hair loss (alopecia) usually lasts longer, progresses over time, and is accompanied by hair thinning, a widening part, or the appearance of bald patches.

To understand the difference, it is important to assess the duration and pattern of hair loss, as well as any associated symptoms.

Key differences between seasonal and hormonal hair loss

Signs of seasonal hair loss

• begins during periods of seasonal change;
• lasts up to 1–2 months;
• hair falls out evenly across the scalp;
• hair density remains unchanged;
• there is no significant scalp itching or excessive oiliness.

This is associated with the physiological transition of some hair follicles into the telogen phase (the resting phase of the hair growth cycle).

Signs of hormonal hair loss

• hair loss lasts longer than 2 months;
• hair becomes thinner;
• the part gradually widens;
• bald patches appear on the crown or along the hairline;
• hair becomes greasy quickly or, conversely, excessively dry;
• scalp itching may occur.

In women, hormonal hair loss is often accompanied by:

• menstrual irregularities;
• acne;
• weight gain or sudden weight loss;
• chronic fatigue.

In men, the most common type is androgenetic alopecia.

Which hormones can affect hair loss?

The following are most commonly checked:

• TSH, T3, and T4 — thyroid hormones;
• testosterone;
• DHEA-S;
• prolactin;
• estrogens (in women);
• ferritin (a marker of iron stores);
• vitamin D.

Hormonal imbalances can disrupt the hair growth cycle and shorten the active growth phase.

When should you see a doctor?

An appointment with a trichologist or endocrinologist is recommended if:

• hair loss lasts longer than 2 months;
• you notice that your part is widening;
• your ponytail has become significantly thinner;
• patches of hair loss have appeared;
• you experience menstrual irregularities or other symptoms of hormonal imbalance;
• your skin condition deteriorates significantly.

Diagnosing suspected hormonal hair loss

The evaluation usually includes:

• blood tests to assess hormone levels;
• ferritin testing;
• vitamin D testing;
• a complete blood count and a biochemical blood test;
• trichoscopy, if necessary;
• a thyroid ultrasound.

A comprehensive approach helps identify the underlying cause.

Can seasonal hair loss turn into hormonal hair loss?

Seasonal and hormonal hair loss have different underlying mechanisms, so one does not literally “turn into” the other. Seasonal hair loss is associated with the natural phases of hair growth and the body’s response to changes in daylight hours, temperature, vitamin D levels, or seasonal stressors. It is usually temporary, evenly distributed across the scalp, and not accompanied by structural changes in the hair follicles.

Hormonal hair loss occurs due to imbalances in thyroid hormones, sex hormones, prolactin, or elevated androgen levels. In these cases, hair gradually becomes thinner, the part widens, overall hair volume decreases, or characteristic areas of thinning develop.

However, seasonal hair loss may reveal an underlying problem. If it lasts longer than 6–8 weeks, becomes more intense, or is accompanied by additional symptoms (weight changes, menstrual irregularities, fatigue, oily skin, or acne), it is worth checking hormone levels. In such cases, a doctor may recommend tests for TSH, T3, T4, sex hormones, and ferritin.

In other words, seasonal hair loss does not itself develop into hormonal hair loss, but prolonged or unusually severe hair shedding warrants further evaluation.

Conclusion

How can you tell hormonal hair loss from seasonal hair loss?

Seasonal hair loss is short-term, evenly distributed, and resolves on its own.

Hormonal hair loss is prolonged and progressive, is accompanied by hair thinning, and often occurs alongside other systemic symptoms.

If hair loss lasts longer than two months or you notice a significant reduction in hair density, it is advisable to undergo an examination and have hormone levels tested.

Early diagnosis can help stop the process and restore the normal hair growth cycle.

Self-medication may be harmful to your health