Mycoplasma bacteria are commonly found on the mucous membranes of the mouth, throat, and genital tract in both men and women. When these bacteria multiply excessively, they can cause infections, most notably Mycoplasma pneumonia.

Coughing up phlegm in the morning is usually not a sign of a serious illness, but if it lasts for a long time or causes difficulty breathing, you should see a doctor to find the underlying cause and get proper treatment.