Sir: Self-medication is behaviour in which an individual uses medicines without medical supervision to treat his own ailment. Self-medication is practised in 60 to 80 percent of cases of distress, ill health or sickness. Self-medication is very common in Pakistan, as many people self-medicate themselves to avoid expenses of visits to doctors. Studies show that there are many disadvantages of self-medication such as misdiagnosis and excessive drug dosage. Paracetamol is very commonly prescribed by most doctors but this drug in large doses can cause liver failure. Similarly, Valsartan is an anti-hypertensive drug, and it is highly effective when used in recommended quantity, but the excessive usage of this drug may leads to heart failure. Moreover, all drugs cause side effects. Self-medication must be stopped in order to avoid further health issues and various hazards that endanger our own lives. SYED MUHAMMAD AHSAN ALI Karachi