Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concern... Coughing up blood is rarely a sign of serious illness in young people who are otherwise healthy. A bleeding from the mouth or throat can cause blood to come out in your saliva when you cough. This is different from coughing up blood from deep within your chest.Blood from your chest is often mixed with mucus. Blood mixed with mucus when coming from lungs may be due to 1.Prolonged, severe coughing 2. Chest infection – this is most likely if your sputum is coloured or contains pus, you will have a fever or a tight feeling in your chest 3.Chronic bronchitis/bronchiectasis – this is a condition that causes excess mucus to build up in the airways 4. Less common condition like pulmonary embolism,tuberculosis,pulmonary oedema, etc So visit your doctor , if problem persist Don t worry you would be fine Hoping your query is solved.