No. 4: Unexplained changes in bowel habits

What's considered normal for bowel movements varies widely. Consult your doctor if you notice unusual or unexplained changes in what's normal for you, such as:

  • Bloody, black or tarry-colored stools
  • Persistent diarrhea or constipation
  • Unexplained urges to have a bowel movement

Changes in bowel habits could signal a bacterial infection — such as campylobacter or salmonella — or a viral or parasitic infection. Other possible causes include irritable bowel syndrome and colon cancer.

No. 5: Confusion or personality changes

Seek medical attention if you have:

  • Sudden confused thinking
  • Confusion about time or place (disorientation)
  • Sudden problems with concentration or memory
  • Sudden personality or behavior changes, such as becoming aggressive

Changes in behavior or thinking could be caused by many problems, including infection, anemia, low blood sugar, dehydration or mental health conditions. Sometimes medications contribute to confusion or personality changes.

No. 6: Feeling full after eating very little

If you consistently feel full sooner than normal or after eating less than usual, get checked by your doctor. This feeling, known as early satiety, also may be accompanied by nausea, vomiting, bloating, fever, and weight loss or gain. If so, be sure to tell your doctor about these signs and symptoms as well.

Possible causes of early satiety include gastroesophageal reflux disease, commonly known as GERD, and irritable bowel syndrome. In some cases, a more serious problem — such as pancreatic cancer — could be a factor.

No. 7: Flashes of light

Bright spots or flashes of light and other visual disturbances sometimes indicate a migraine. In other cases, sudden flashing lights could signal retinal detachment. Immediate medical care can help prevent permanent vision loss.

Jul. 14, 2011 See more In-depth