Have you noticed small bald patches appearing on your scalp? You may have alopecia areata and be wondering what it is and why it occurs. In this article, we explain its causes and symptoms. However, as we always recommend, if you think you may have this condition, it is essential to consult a specialist for an accurate diagnosis and appropriate treatment.
What is alopecia areata?
Alopecia areata is one of the many types of alopecia and has several specific characteristics:
- Hair loss can occur in different areas of the body, including the scalp, eyebrows, beard, pubic area and armpits.
- Hair loss occurs in rounded patches.
- There are no visible changes to the skin, inflammation, flaking or dermatitis. Instead, the hair follicle is affected, causing hair growth to stop.
This type of alopecia can be diagnosed through a clinical examination and trichoscopy.
Types of alopecia areata
Hair loss caused by alopecia areata can occur in different areas of the body and may present as a single patch, multiple patches, diffuse hair loss, total hair loss or universal hair loss.
Depending on the extent and location of the hair loss, alopecia areata can be classified into several types, which can be diagnosed during the initial consultation with a hair specialist.
Patchy alopecia areata
This is the most common type of alopecia areata and causes round patches of hair loss. Depending on the affected area, it may involve a single patch in one part of the scalp or multiple patches across the scalp.
Alopecia totalis
As its name suggests, alopecia totalis affects the entire scalp, causing complete loss of scalp hair.
Alopecia universalis
In this type of alopecia areata, hair loss affects all areas of the body, including the eyebrows, armpits and pubic area, rather than just the scalp.

Causes of alopecia areata
You may be wondering why alopecia areata develops. Although its exact cause is not fully understood, several contributing factors have been identified:
- Autoimmune factors
- Emotional or psychological stress
- Other associated medical conditions
In some cases, family history also plays an important role. However, alopecia areata is primarily considered a multifactorial condition.
Stress
Stress has been identified as one of the factors that can trigger alopecia areata, although it is not the only one.
It is believed that situations involving emotional, physical or psychological stress can trigger an immune response in people who are genetically predisposed to the condition.
Therefore, learning to manage and reduce stress may help prevent certain future episodes of alopecia areata.
Genetics
Genetics also plays an important role in the development of alopecia areata. Having a family history of the condition increases the likelihood of developing it.
Nevertheless, as mentioned earlier, environmental and autoimmune factors also play a significant role in triggering alopecia areata.
Other factors
Autoimmune factors are the main cause of alopecia areata. The immune system mistakenly attacks the hair follicles, weakening them and causing hair loss.
These factors, combined with environmental and genetic influences, contribute to the development of alopecia areata.
Main symptoms
When alopecia areata develops, certain symptoms are common across cases, particularly hair loss in specific areas and fragile hair.
Some people may also experience scalp pain, although this is relatively uncommon.
Hair loss in specific areas
This is the most characteristic symptom of alopecia areata, as it causes distinct patches of hair loss.
These patches are usually round or oval and appear without skin flaking or inflammation.
Scalp pain
In general, alopecia areata does not cause scalp pain. However, in certain cases, it may lead to irritation or mild sensitivity because the skin in the affected area becomes more delicate.
Fragile hair
Hair fragility is another common symptom of alopecia areata.
As the hair follicles are attacked, the hair gradually weakens, becoming finer, more brittle and more prone to breakage, ultimately leading to hair loss.