How to… spot serious medical symptoms?

Here are "five flags" - five medical symptoms - you should keep in mind:

1. If you have unexplained weight loss and/or loss of appetite , you may have a serious underlying medical illness.

"If you're on a diet, you're expecting this to happen. But if you're eating the same way - and now have to adjust your belt a few notches tighter - you could have a serious problem, so you should see a doctor." Shulman says.

2. Slurred speech, paralysis, weakness, tingling, burning pains, numbness, and confusion are signs of a stroke, and you should get to an appropriate emergency centre immediately. Early treatment may prevent permanent damage to the brain or even save your life.

3. Black, tarry stools may indicate a haemorrhage from an ulcer of the stomach or the small intestine. It is important to stop the bleeding and to rule out cancer as a cause.What you eat changes the colour of stools. But black, tarry stools mean there may be bleeding higher in the digestive tract, says Shulman. It could be a sign of a bleeding ulcer or cancer.

4. A headache accompanied by a stiff neck and fever is an indicator of a serious infection called meningitis. In fact, if you can't put your chin on your chest, that's a sign you may have bacterial meningitis, says Shulman. With bacterial meningitis, you need antibiotics immediately to kill the bacteria before it infects and scars the brain.

5. A sudden, agonizing headache, more severe than any you have felt before, could mean you are bleeding in the brain. Go to an emergency room immediately. A brain aneurysm is rare, but it can happen - even in people under 40. If you have a severe, crushing headache, you may have an aneurysm, which is a blood-filled pouch bulging out from a weak spot in the wall of a brain artery. If treated before it bursts, it could save your life.