Mesothelioma Symptoms by Type: Pleural and Peritoneal

Mesothelium is the thin tissue that lines the lungs, the abdomen, the heart, and other organs. Mesothelioma is cancer of that lining. It most often starts in the chest, but it can start in the abdomen or elsewhere.

That location decides the symptoms. Cancer in the chest lining presses on breathing. Cancer in the abdominal lining presses on the gut. The rest of this page follows that split.

NCI's symptom page is short and specific. It names shortness of breath and pain under the rib cage first. It then adds that the cancer sometimes makes fluid collect in the chest or the abdomen.

The full list of signs to check with a doctor:

• Trouble breathing.
• Cough.
• Pain under the rib cage.
• Pain or swelling in the abdomen.
• Lumps in the abdomen.
• Constipation.
• Problems with blood clots, meaning clots that form when they should not.
• Weight loss with no known cause.
• Fatigue, or feeling very tired.

NCI is careful to add that any of these can come from the fluid, from the cancer, or from something else entirely.

Pleural mesothelioma grows in the pleura. That is the double layer of tissue wrapping each lung and lining the chest wall.

Trouble breathing usually comes first. Often it is not the tumor itself doing the work. It is fluid. A pleural effusion is a pool of fluid between the two layers of the pleura, and it squeezes the lung from outside. NCI's summary for doctors puts a number on it. Effusions, in the chest or the abdomen, are a major symptom problem for at least 66% of patients.

Cough and pain under the rib cage follow. The pain is often described as dull and steady rather than sharp.

Peritoneal mesothelioma grows in the peritoneum, the lining of the belly. Its symptoms read like a digestive problem: pain in the abdomen, swelling, lumps that can be felt, and constipation.

Fluid can gather here too, which is what produces the swelling and the feeling of tight fullness. Weight loss and fatigue can come with disease at either site.

Blood clots are on NCI's list, and they are easy to miss as a cancer sign. Cancer can push the blood toward clotting. A clot in a leg vein or a lung can be the first thing that sends someone for scans. Our overview of mesothelioma covers the disease more broadly.

This is the part that trips people up. NCI does not publish a fixed number of years. It says only that it usually takes a long time for mesothelioma to form after asbestos exposure. Its asbestos fact sheet adds that symptoms may not appear for many decades.

Published research does give figures. A study of 1,933 patients treated through Korea's asbestos health centers calculated an average latency of 33.7 years for mesothelioma. A separate review reports a median near 40 years across various registries. In that study, people exposed while making asbestos products had the shortest latency. Those who worked in or lived near asbestos mines had among the longest.

Three decades is a long time. A shipyard job, an insulation trade, a school building, or a home repair stops feeling tied to a new cough. Yet NCI reports that asbestos exposure turns up in about 70% to 80% of cases. So the history is worth raising, even when it feels like ancient news. Our page on asbestos and cancer covers which trades carried the heaviest exposure.

NCI's asbestos fact sheet lists a wider set of symptoms for anyone with an exposure history. It advises checking with a doctor for:

• Shortness of breath, wheezing, or hoarseness.
• A cough that keeps getting worse.
• Blood in sputum coughed up from the lungs.
• Pain or tightening in the chest.
• Difficulty swallowing.
• Swelling of the neck or face.
• Loss of appetite.
• Weight loss.
• Fatigue or anemia.

Those symptoms do not point only at mesothelioma. They also fit asbestosis, pleural thickening, pleural plaques, and lung cancer.

Symptoms are vague. The tissue itself is also hard to read. NCI's clinical summary is direct here. Attempts to diagnose by cytology or needle biopsy of the pleura often fail. Telling mesothelioma from adenocarcinoma in a small sample can be very hard. Thoracoscopy uses a camera inside the chest to take bigger samples. NCI calls it valuable for getting enough tissue.

Pathologists lean on specific stains. Pancytokeratin stains are positive in nearly all mesotheliomas. Four more stains help identify the epithelioid type: cytokeratin 5 and 6, calretinin, WT-1, and D2-40. That type is roughly 60% of diagnoses. Chest x-ray is still the most common first test for asbestos disease. It cannot show asbestos fibers themselves.

NCI does not publish a split between chest and abdominal cases. It does not publish a symptom screening interval, or a latency figure of its own. Any page giving a precise share of cases by site goes past what NCI says. The honest version is simpler. Chest symptoms are the common opening. Abdominal symptoms are the second pattern. The exposure history is the detail most likely to speed things up.

• National Cancer Institute, Mesothelioma Symptoms, updated May 16, 2025, accessed August 6, 2026
• National Cancer Institute, Malignant Mesothelioma Treatment (PDQ) - Health Professional Version, updated May 12, 2025, accessed August 6, 2026
• National Cancer Institute, Asbestos Exposure and Cancer Risk, accessed August 6, 2026
• MedlinePlus, Mesothelioma, accessed August 6, 2026
• Huh DA, Chae WR, Choi YH, et al., Disease Latency according to Asbestos Exposure Characteristics among Malignant Mesothelioma and Asbestos-Related Lung Cancer Cases in South Korea, Int J Environ Res Public Health 2022;19:15934, accessed August 6, 2026
• Klebe S, Hocking AJ, Soeberg M, Leigh J, The Significance of Short Latency in Mesothelioma for Attribution of Causation, Int J Environ Res Public Health 2021;18:13310, accessed August 6, 2026