Another warning sign? That uh-oh feeling that tells you something's not quite right. "You know your body best," says Len Lichtenfeld, M.D., deputy chief medical officer at the American Cancer Society. "When you see or feel something different or just feel 'off,' pay attention; don't dismiss it."
Here are nine symptoms and what they might mean.
What else it might be: Shingles can cause pain in the forehead before the notorious skin reaction (shingles is a painful flare-up of the herpes zoster virus that lies dormant in anyone who's had chicken pox). Contrary to common belief, sudden severe headaches are unlikely to be a sign of a brain tumor. Rather, research shows that two-thirds of patients diagnosed with a brain tumor experienced tension headaches — dull, achy or pressure-like pain — that steadily worsened over a period of weeks to months.
Sudden severe chest or upper-back pain (often described as a ripping sensation) can be caused by a tear in the aorta, known as aortic dissection, which requires immediate attention. Fortunately, this life-threatening condition occurs in only about three out of 100,000 people.
What else it might be: "Perhaps 10 to 20 percent of cases of intense chest pain are due not to heart trouble but to gastrointestinal reflux disease [GERD]," says Topol. Rarely, it could also signal esophageal spasm, an abnormal contraction of the muscles in the esophagus, which carries food from the throat to the stomach. Both conditions can be treated with medications, but it's always wise to go to the ER: "It's a heart attack or angina until proven otherwise," Topol says.
3. Unexplained Weight LossThe big worries: Losing more than 5 percent of your body weight — without trying — over a period of six months could mean cancer: Weight loss is a symptom in up to 36 percent of cancers in older people. "If you or a family member is suddenly losing weight after trying 400 times before, you have to ask, 'Why is this time the charm?' " says Lichtenfeld.
What else it might be: Endocrine disorders are a common cause of unintentional weight loss. Of those with an endocrine disorder (especially hyperthyroidism, an overactive thyroid), up to 11% experience weight loss. The condition also triggers restlessness, sweating, increased appetite and difficulty concentrating.
If your weight loss is accompanied by extreme thirst or hunger, fatigue and frequent urination, it could be a sign of diabetes.
Gastrointestinal conditions like inflammatory bowel disease and celiac disease cause weight loss as well — in addition to symptoms such as diarrhea and abdominal pain.
Depression and other psychiatric conditions could be to blame, too. "Decreased appetite and weight loss are very common symptoms of depression," says Susan G. Kornstein, M.D., professor of psychiatry and obstetrics/gynecology at Virginia Commonwealth University. "But patients with unexplained weight loss should undergo a workup to rule out general medical causes."