You probably feel congested and are blowing your nose more often than normal. “Our immune system produces more white blood ...

Mucus serves an important purpose in the nasal passages and other cavities ... This type of infection can cause bleeding in the airways, and this blood makes the mucus and phlegm appear dark ...

Another upper respiratory infection that can cause a metallic taste when coughing is a sinus infection ... A small amount of blood in the phlegm or mucus you cough up during a cold is normal.

Antihistamines are helpful in decreasing mucus production and drying out our nasal passages ... oral decongestants like Sudafed can cause high blood pressure, high heart rates and difficulty ...