Cancers like ovarian, colon (colorectal), and sometimes cervical cancer can cause bloating and weight gain, often due to fluid buildup (ascites) or obstructions in the abdomen, leading to swelling, pressure, and digestive changes like constipation, which can manifest as unexplained weight gain despite potential loss of appetite. Treatments like chemotherapy or steroids can also contribute to weight gain, while persistent bloating, abdominal pain, or changes in bowel habits warrant immediate medical attention.
Symptoms of ovarian cancer include frequently (roughly 12 or more times a month) having: a swollen tummy or feeling bloated.
Persistently feeling bloated and full is one of the most common early signs of ovarian cancer.
Certain types of cancer can cause weight gain. Ovarian and colorectal cancer, for example, may cause fluid buildup in the legs or abdomen. This type of edema is called ascites.
Some general signs and symptoms associated with, but not specific to, cancer, include:
When cancer is suspected there is a fast route within the NHS to get further tests and specialist advice to rule out cancer. These are called 2 week wait referrals and you should be seen within 2 weeks of being referred.
The first warning signs of stomach cancer often mimic common issues like indigestion, including persistent heartburn, bloating after small meals, abdominal discomfort or pain, nausea, loss of appetite, and unexplained weight loss, along with changes in bowel habits or blood in vomit/stool. Because early stages rarely show symptoms, these signs are easily mistaken for less serious problems, making prompt medical evaluation essential if they are persistent or worsening.
Certain medical conditions can lead to unexplained weight gain. These conditions may include: Endocrine disorders. These include conditions like thyroid hormone deficiency, insulin resistance and polycystic ovary syndrome (PCOS).
Regardless of whether the adrenal tumor is causing Cushing's or subclinical Cushing's syndrome, one of the most common universal features of the excess cortisol is weight gain, typically involving the face, neck, or belly. Often, the legs tend to lose fat, and become very slender.
More serious disorders that may cause bloating are:
Gastric cancer red flags include a history of ulcers, unexplained abdominal pain that doesn't respond to treatment with proton pump inhibitors, unexplained weight loss, lack of energy, discomfort swallowing, nausea and vomiting blood. A palpable abdominal mass indicates advanced disease.
Bloating, diarrhea and abdominal pain are three of the most common ovarian cancer symptoms. The bloating can be so severe that it distorts your appearance. Feeling full quickly and heightened fatigue are two other ovarian cancer symptoms.
Early pancreatic cancer often has no symptoms, but common first signs when it does appear include unexplained weight loss, abdominal/back pain (especially worsening after eating), jaundice (yellow skin/eyes), changes in stool/urine, new-onset diabetes, or digestive issues like nausea/vomiting or bloating, notes Cancer Council, Pankind, Mayo Clinic, and Pancreatic Cancer Action Network.
His case is a reminder that even seemingly minor symptoms—such as fatigue, unexplained pain, weight loss, and skin discolouration—should never be ignored. Another survivor, Dan Godley, has been given the all-clear from pancreatic cancer.
Adrenal Tumor Symptoms
Get a mammogram and clinical breast exam every year to check for breast cancer. Get a Pap test and HPV test every five years to check for cervical cancer and HPV. Talk to your doctor about whether you need screening after age 65. Get a colonoscopy every 10 years to check for colorectal cancer.
These tumors can cause a range of symptoms:
Hashimoto's disease is a chronic autoimmune disease that affects your thyroid gland. It can cause lower-than-normal levels of thyroid hormone in your body. This affects several areas of your body and causes symptoms like fatigue, weight gain and constipation.
These exams and tests often include:
What causes obesity & overweight?
Symptoms if cancer spreads to the tissue lining your abdomen (peritoneum) You might have a swollen tummy (abdomen) if your cancer has spread to the tissue that lines your abdomen (peritoneum). The swelling is due to a build up of fluid called ascites. It can make your clothes feel tighter.
Early Cancer Warning Signs: 5 Symptoms You Shouldn't Ignore
If your GP or another healthcare professional thinks your symptoms might be linked to cancer, they can refer you for urgent tests. The NHS aims to complete these tests and give you results within 28 days of your referral.