Are you taking antibiotics very often ? If so, that is quite concerning.
If I get a cold* or whatever, I don't take prescriptions, I take daily vitamins and minerals. The human immune system can fight most common ailments, as long as it has access to a ready supply of 'raw materials' to build millions of fighting cells to attack the infection.
* Colds are not caused by bacteria, so antibiotics are of no use in that particular case.