Dandruff can result from several factors, both physiological and environmental. Here are some common causes:

1. Malassezia Fungi: One of the primary causes of dandruff is an overgrowth of a yeast-like fungus called Malassezia globosa. This microorganism naturally occurs on the scalp of most adults but can cause problems when it grows out of control, breaking down scalp oils (sebum) into byproducts that irritate the scalp, leading to flaking and itching.
2. Seborrheic Dermatitis: A more severe form of dandruff, seborrheic dermatitis, involves red, greasy skin covered with flaky white or yellow scales. It affects areas rich in oil glands, like the scalp, face, and chest.
3. Skin Irritation or Sensitivity: Some people are more sensitive to hair care products or environmental factors, which can irritate the scalp and trigger dandruff.
4. Dry Skin: Dandruff can also occur when the scalp becomes too dry, causing small, dry, white flakes to appear.
5. Oily Skin: An overly oily scalp can contribute to dandruff by creating a favorable environment for the growth of Malassezia fungi.
6. Stress: Prolonged stress can weaken the immune system and make the body more susceptible to fungal infections, including those that cause dandruff.
7. Hormonal Changes: Hormonal fluctuations, such as those during puberty or due to stress, can affect the oil production of the skin, potentially leading to dandruff.
8. Poor Hair Care Habits: Infrequent shampooing or improper hair cleaning can allow dead skin cells and oil to accumulate, promoting dandruff formation.
9. Health Conditions: Certain health conditions, including Parkinson’s disease, HIV/AIDS, and some neurological disorders, can increase the risk of dandruff due to their effects on the immune system or skin health.
10. Weather: Cold, dry winter weather can exacerbate dandruff by drying out the scalp, while hot, humid summers can stimulate oil production and fungal growth.

Understanding the underlying cause of your dandruff can help guide the selection of the most appropriate treatment method.