Symptoms aren't exactly warning signs, but the effects. Often those effects spread the disease. You get a cold or repository infection. You cough and or sneeze. Spreading germs all over. That's the disease hijacking your system to spread itself. So stopping the coughing/sneezing is usually in everyone's best interest.
There is little to be don than let something like a common cold run its course, but we can clear up aches/pains, stuffy nose, etc.
Again, applying to mild symptoms like a common cough and cold.
I feel I should mention a cough that does not go away without any other symptoms may be a warning sign of cancer.
