If you don't get enough sleep, dark circles may appear under your eyes, particularly if you sleep for no less than 7 to 8 hours every night. They can also be the result of something different such as anemia - a health problem that occurs when the body doesn't produce enough red blood cells. 

2. Color changes on your fingers
Noticed that your fingers change color often? There is a serious reason why this occurs. It is a sign that you have Reynaud's Syndrome - a condition where low temperatures cause spasms in the blood vessels, causing changes in the color of the skin on your fingers. 

If your eyes have become tired or you've begun to notice that you occasionally find yourself unable to recognize people or read road signs from a normal distance, you may have developed short-sightedness or astigmatism. Be sure to visit an optician. 

4. Blobs in front of your eyes
Dots or strips may suddenly appear in front of your eyes and usually, in the presence of bright white lights. If you see them for over a week, consult an optician as this might mean an early indication of cataracts or some other serious problem with your vision.

This is caused by the processes at work in your intestine. If it occurs rarely, then there's nothing to worry about. If you notice your stomach making noises on a regular basis, or if they're accompanied by pain, then you should visit your doctor straight away. 

6. Peeling skin
If you notice your skin peeling, this may be an indication that your body is lacking vitamins. If you eat a balanced diet, your skin should return back to normal. If the peeling is accompanied by an itch, visit your doctor as soon as possible as this may be an indication of a fungal infection. 

The reduction in the keenness of your sense of smell as you get older occurs as a consequence of damage to the nervous system. But if you’re relatively young and have begun to notice that you’re losing your sense of smell, you should go and see a doctor right away. It could be the result of either a strong cold or other viral infection.

8. Twitching eyelids
If you've noticed a prolonged twitching of the eyelids, it can indicate that your eyes have been overworked. Overcome this by washing your eyes with cotton pads soaked in cold water. If this doesn't work and the twitching continues speak to a neuropathologist. This could be a sign of a serious problem with your nervous system. 

Tinnitus is a ringing or noise in your ears. While most people try not to pay attention to this sensation, believing that it doesn't threaten their health in any way, constant ringing is quite possibly caused by an illness. The most widespread cause of a ringing sound in the ears is the constant loud noise that occurs in certain kinds of work environment. 

10. Dislocation of the shoulder joint
For some people, their shoulder joints may appear to be loose or can be moved in an unusual number of directions. This is an indication of an unstable shoulder joint - a condition where the ball of the shoulder bone comes out of the socket of the joint. While it may be that individuals were simply born with very flexible ligaments, or it could have been caused by a sports injury. In both cases, this is a dangerous condition that can lead to injuries and dislocation.