Some patients may experience blood in their sputum when coughing with a cold, and this may be very infrequent, just a few mouthfuls, most often due to a break in the mucous membrane of the throat caused by the force of the cough.
If you cough up a large amount of blood, a whole mouthful of blood, or if you continue to have blood in your sputum, you need to seek medical attention. The patient may not simply have a cold cough, but the cough may be a symptom of another illness, especially if you cough up a large amount of blood.