Diabetes is a condition that involves the elevation of blood sugar levels above normal. Long standing diabetes is known to cause damage to the target organs of the body. These are the eyes, kidneys, brain, peripheral blood vessels and nervous system. Complications appear early and are more severe with uncontrolled diabetes. Affliction of the peripheral nervous system is well known, which is manifested by tingling, numbness and or a burning sensation in the hands and feet. But involvement of autonomic nervous system (system responsible for involuntary functions like heartbeat, intestinal movements, and etcetera, is more subtle and less known by people. This may be associated with other diabetic complications or can occur independently. As the intestinal motility is affected, a person may develop chronic diarrhoea or constipation. Stasis of food in intestines due to constipation leads to overgrowth of bacteria, which results in recurrent infections and diarrhoea with or without abdominal pain. Absorption of food as well as that of anti-diabetic medication is impaired due to reduced intestinal motility. As a result, the body gets deprived of necessary nutrients over a period of time. Blood glucose levels are deranged, leading to sudden low or high levels. A person starts suffering from low blood pressure, because of affliction of the autonomic nervous system. The blood pressure falls and becomes very low as one stands up from a sitting or lying down position. Because of this, one tends to feel giddy while standing or walking. Heart rate also tends to be disturbed because of disturbance of the autonomic nervous system. This is because the heart fails to adjust its rate according to the stress. This also contributes to feeling dizzy and fainting. Urinary system is also affected by autonomic neuropathy in diabetics. There is difficulty to pass urine leading to retention in extreme cases, as the nervous control over bladder is damaged. Stasis of urine, even in small quantities, becomes a source for germs to grow, causing recurrent urinary tract infections. Infection is further aggravated due to high blood glucose levels. Due to infection of the urinary tract, one suffers from increased frequency and urgency of urination. Sexual impotence is the most troublesome problem created due to autonomic neuropathy. Diabetic neuropathy is the most common organic cause for erectile dysfunction in a young man. Use of alcohol and tobacco further aggravate the problem, as autonomic neuropathy is intensified. Many times, diabetes is diagnosed when a person develops any of these complications. A sufferer may develop one or more features of autonomic neuropathy. For example, a person may have altered bowel movement along with orthostatic hypotension. A high index of suspicion is needed to diagnose diabetes in face of autonomic neuropathy. Unfortunately, once the autonomic nervous system is damaged there is no medicine to revert it. Drugs like gabapentin (an anticonvulsant), B complex, and etcetera, are used but only provide transient relief. Avoiding standing for a long time and sitting with your legs spread in front can reduce postural hypotension. Use of elastic stockings or crepe bandage while standing or walking also helps in minimising postural hypotension. Regular physical exercise and warm baths are also useful. To prevent such troublesome complications it is imperative that diabetes should be diagnosed at the earliest stage. Screening all middle aged persons for diabetes is a good strategy. A very good control of diabetes by means of diet restriction and anti-diabetic drugs can delay or minimise the development of complications including neuropathy. Avoiding alcohol and smoking is helpful in reducing the suffering. A known patient of diabetes should be cautious to see that autonomic neuropathy does not develop. Dr Rachna Pande, Specialist, internal medicine rachna212002@yahoo.co.uk