My son siddhant aged 14 years is getting weak and thin day by day since last 2-3 months. Earlier his body weight was around 79-80 kg. But at present his body weight is reduced to 69-70 kg. He is looking weak, thin and exhausted. However his height got increased during last two to three months. Earlier i.e.before 3-4 months his waist size was 38 now his waist size reduced to 32-33. please suggest that there is any medical problem to my son or not? His diet also decreased in comparison of earlier diet.