Why Does Ovarian Cancer Cause Bloating

Bloating is one of the most common and noticeable signs of advanced ovarian cancer. Due to a buildup of fluid (ascites), a woman’s belly can become swollen and distended. The bloating may be accompanied by pain or an uncomfortable feeling of tightness around the stomach, as well as indigestion and an increased need to pass gas. Additionally, the resulting pressure on the stomach can cause loss of appetite, while the resulting pressure on the lungs can cause shortness of breath.

Where does the fluid come from?

The fluid buildup responsible for the bloating associated with ovarian cancer can happen in several ways:

• If ovarian cancer spreads to the membrane (most common) that lines the inside of the abdominal wall or peritoneum, it can cause irritation and stimulate the membrane to produce excess fluid.
• If ovarian cancer spreads to the liver or the vein that carries blood to the liver, blood pressure may rise (a condition known as portal hypertension). Increased pressure in the portal blood vessels may cause protein-containing (ascitic) fluid to leak from the surfaces of the liver and intestines and accumulate around the stomach.
• If ovarian cancer blocks the lymphatic system, lymph will not drain well and may instead begin to pool around the stomach.

Bloating can have many causes

Bloating is sometimes a sign of ovarian cancer, and any unusual bloating should be brought to the attention of an obstetrician gynecologist or primary care physician right away. With that said, there are many other possible—and more likely—reasons for it. Some potential causes include gas, constipation, irritable bowel syndrome (IBS), side effects of certain medications, a high-sodium diet, weight gain and natural changes that occur during a women’s menstrual cycle.

Medically reviewed by Mian Shahzad, MD, PhD, gynecologic oncologist.

If the bloating is deemed suspicious after an initial consultation and you'd like to discuss your unusual bloating or other ovarian cancer symptoms with a specialist at Moffitt Cancer Center, you can request an appointment by calling 1-888-663-3488 or completing our new patient registration form online.