Chest Pain. Such pain could be a symptom of indigestion, a heart attack or another condition.

Coughing up blood. Blood in sputum could indicate simple bronchitis or irritation of the trachea -- but it could also be the result of pneumonia or lung cancer.

Blood in the urine. Though it may indicate a simple kidney or bladder infection, this symptom could also mean something more serious, such as a kidney stone or even a malignancy.

Rectal bleeding. Blood in the stool could be from hemorrhoids, or it could be caused by an active ulcer or colon cancer. Bright-red blood indicates active bleeding.

Unusual sores, lumps or lesions. Usually, these symptoms are benign, but you should have them checked by a doctor to make sure theyâre not cancer.

Slurred speech and/or weakness on one side. These symptoms may likely indicate youâre having a stroke.