Some particular factors can increase the chances of developing blackheads such as:
• Excess oil production from the sebaceous gland.
• Increased activity of Propionibacterium acne bacteria on the skin.
• Frequent irritation of the hair follicles caused by dead skin cells that do not shed regularly.
• Hormonal changes caused during puberty, menstruation, and while taking birth control pills may cause increased oil production from the sebaceous gland.
• Side effects of certain drugs such as corticosteroids and lithium.
It is also believed that diet plays an important role in causing blackheads. Certain types of foods that have the ability to increase blood sugar levels such as carbohydrates and dairy products may be a triggering factor for blackheads formation. Some people believe that what you eat or drink can affect acne.