Hello, You are experiencing occasional fainting spells. You already have had cat scan done and everything came out normal. You are very young to get fainting spells. Try to stay away from stress (physical and emotional), avoid addictions if any (smoking, alcohol, drugs, etc). Do not skip meals, take home made nutritious (rich in iron, calcium and protein) food over junk food. Take food that is healthy and substantial. Poor general health condition, weakness, anemia, low blood pressure, low blood glucose, dehydration are some common causes of fainting spells. Avoid over-exhaustion and take adequate sleep. Lack of quality sleep may trigger symptoms. Make sure you are not dehydrated, take fruit juice, soups and fluids so that your blood electrolyte system remains normal. You are suggested to take a complete health check up together with all required tests and investigations to detect any pathology causing you symptoms, so that treatment can be started at the earliest. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician