Your tongue is enough to indicate the health issues you might be undergoing through.Let  us see how?? 

Yellow coating on tongue :Ideally the colour of coating on our tongue should be thin and white in colour. Yellow coating is an indication of excess heat in your body  , it Is  also the result of  trapped dead skin cells, bacteria or discolouring particles on the surface of tongue.

Crack or fissures at the tip of tongue : This is an indication of congestion in your heart. 90% of case of acute heart failure is the result of congestion, a manifestation of fluid build up due to increased blood pressure. Practising yoga might help you to get rid of this issue. 

Teeth indentations are indication of maladsorption of nutrients in the body probably due to weak digestive system. B12 deficiency makes the tongue sore and beefy red in colour. Iron deficiency,  low haemoglobin, deficiencies of vitamin and zinc causes swollen tongue or burning sensation in your  tongue .Inclusion of carrots, beetroots  pomegranates, apples, corns in your diet will surely increase your haemoglobin. 

Overly shiny or extremely dry tongue indicates that your diet lacks  nutritional value  It is also indicative of your unhealthy ( junk foods) eating practices. Do increase your intake of homely foods including green vegetables and fresh fruits. 

Trembling tongue or deep cut at the center of the tongue indicates problems in your nervous system, means either you are in stress ,tension resulting in subsequent mood changes and restlessness .Medidation is the best way to relief stress 

Bluish purple tinge, thick veins underside of your tongue is an indication of blood stagnation,it simply means that healthy food is not reaching your body. To check the vitality of your body, try  to move your tongue tracing the geometric shape circle, if you are able do it with ease ,good but if not, it  indicates weak body .To get rid of it increase milk, and lentils consumption in your diet .

Pale tongue ,watery tongue ,thick tongue, bubbles of saliva on your tongue is a sign of imbalanced diet. Hair on your tongue is an indication of oral leukoplakia. It generally happens to people infected with viruses like HIV. White cold sores are small ulcers generally formed along the perimeter of tongue, it is indicative of the fact that u might have been infected with herpes simplex virus. 

Try to listen to your tongue symptoms and act accordingly  as early as possible to live a healthy life.