Sir: Most people are not aware of the importance of donating blood. There are many advantages of donating blood that include the formation of new blood cells and a reduction in the chances of heart attack, liver failure, high blood pressure and blood sugar. It also helps in burning extra calories and assists in curtailing obesity. Moreover, the formation of new blood cells brings a glow to the skin. However, a donor should always be aware of some major points before donating blood. First of all, the blood donor should be a healthy person, aged 18 years and above and weighing more than 50 kilogrammes. Secondly, the standard quantity of a onetime blood donation should not be more than 470 milliletres. This is about eight percent of the average volume of an adult’s blood. The body replaces this volume within 24 to 48 hours, and replenishes red blood cells in 10 to 12 weeks. Thirdly, the donor should ensure that the needle and bag being used for drawing blood are sterilised. Further, after donating blood, the donor should take rest for at least five minutes and should drink at least one glass of juice. There should always be a gap of at least three months between each blood donation. Lastly, regular drinkers (alcoholics), drug addicts, pregnant women, people having diseases such as HIV or Hepatitis C should not donate blood.Some of the famous blood banks in Karachi are: P W A (Civil Hospital), Hussaini Blood Bank, Edhi Blood Bank, Aga Khan University Hospital, Fatimid Blood Bank, Red Crescent, etc. It is important to create awareness among the masses about blood donation as this helps in overcoming many misconceptions that people have in this regard. Blood donation can help save many precious lives.SIDRA AJMALKarachi