Risk factors

Smoking.
Excessive alcohol intake.
Obesity.
Exposure to environmental pollutants and toxins.
Systemic Diseases such as Liver diseases, Diabetes mellitus (DM) and HTN
Psychological factors such as Anxiety, Stress, Anorexia nervosa.
Malnutrition.
Endocrine diseases such as Hypothyroidism and Hyperthyroidism.