Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Fatigue is the most common cause of dark circles under your eyes. Since he is not been able to eat well since the last few days he may be dehydrated. I suggest you to take him to a doctor. Mild to moderate dark circles often respond well to simple and inexpensive treatments, such as: 1. Cold. Dilated under-eye blood vessels may contribute to dark circles under your eyes. Try holding a cold compress, a chilled teaspoon or a bag of frozen peas wrapped in a soft cloth against the area to make these vessels constrict. 2. Extra pillows. Elevate your head with two or more pillows to prevent puffiness that develops when fluid pools in your lower eyelids. 3. Extra sleep. Although short nights don t usually cause under-eye circles, a lack of sleep may make you paler, so shadows and circles you already have become more obvious. Sometimes, what appear to be dark circles under eyes may merely be shadows cast by puffy eyelids or hollows under eyes that develop as a normal part of aging. Some of the most common causes of true under-eye circles are: 1. Allergies 2. Atopic dermatitis (eczema) 3. Contact dermatitis 4. Fatigue 5. Hay fever (allergic rhinitis) 6. Heredity 7. Pigmentation irregularities, which can be a particular concern for people of African or Asian ancestry 8. Rubbing or scratching your eyes 9. Sun exposure, which prompts your body to produce more melanin, the pigment that gives skin its color 10. Thinning skin and loss of fat and collagen that comes with aging, which can make the reddish-blue blood vessels under your eyes more obvious. Take him to a doctor who will find out the root cause and treat appropriately. Regards Dr Sanjay Kini