With onset of summer, my legs have started to swell. In the summer months of previous years, only my feet used to swell. This time, my legs below the knee are swelling during the day. It is worse when I wear  flats and sandals. What could be the reason for the swelling? — Meera It commonly occurs among people with prolonged physical inactivity, prolonged periods of standing or sitting, genetic, heat, burns, pregnancy, menstrual cycle, pills, menopause, excessive salt intake, certain medications, malnutrition, heart failure, renal damage, liver and lung disorder, diabetes, allergies, low albumin, heart disease, and I could go on. And we are talking about leg or pedal edema. The word ‘edema’ is derived from Greek word oidema, meaning “a tumour or swelling, also known as dropsy, hydropsy”. It is caused by the retention of excess fluid within the body’s tissues and when the capillaries (tiny blood vessels) leak fluid into the surrounding tissue, the area will start to swell. This could be due to capillary damage or increased pressure. Pedal edema as in your case is the accumulation of fluid in the feet and lower legs, known as dependent edema. It is typically caused by one of two mechanisms — venous edema which is caused by increased capillary filtration and retention of protein poor fluid from the venous system into the interstitial space; and lymphatic edema, which is caused by obstruction or dysfunction of lymphatic outflow from the legs resulting in accumulation of protein rich interstitial fluid. These two mechanisms can operate independently or together. If the damage is due to lymph edema it is called primary lymph edema. Secondary lymph edema is caused by disease or medical condition, such as an infection or cancer. Any blockage, such as a clot in one of the veins can impede the flow of blood. This causes an increase in pressure in the vein, which may result in leakage of fluids into the surrounding tissue, causing edema. Some of the common initial investigations would be an chest X-ray, blood tests, urine tests, liver function tests, heart function tests. In order to treat the edema, it is imperative to diagnose the condition that is causing it. Treatment like in any other cases depends largely on the cause of the edema. Treatments for some conditions may be curative (example dis-continuing an edema causing medication). More commonly, a completely reversible cause is not identified, and treatment is aimed at reducing swelling by improving lymphatic drainage and decreasing capillary leakage. This is typically accomplished by non-pharmacologic treatments — external compression stockings, lymphatic massage, modification of sodium/protein intake and lastly pharmacological treatment. Common recommendations include — down salt consumption; to lose weight if the patient is overweight; do regular exercise; raise the legs several times per day to improve circulation; rear supporting stockings; not to sit/stand still for too long, get up and walk about regularly when travelling by car, train, boat or plane; avoid extremes of temperature, such as hot baths, showers, and saunas; dress warmly if it is cold, and massage. Then there are drugs that raise the rate of urination, providing a means of forced diuresis (increased production of urine by the kidney) thereby getting rid of the edema. Do consult a general physician with the above information in mind. •    Dr Sanduk Ruit Medical Director, Tilganga Eye Hospital •    Dr Bhagwan Koirala Cardiac Surgeon,TUTH •    Prof Upendra Devkota Chief of Neurosurgery, National Institute of Neurological and Allied Sciences •    Dr Kundu Yangzom Chief of OBGYN Services, Patan Hospital •    Dr Kishore PandeyPediatrician, CIWEC •    Dr Sameer AryalDentist, Advanced Dental Care •    prof Dr Dwarika P Shrestha Head of Dermatology Department, Teaching Hospital andConsultant,DermatoVenereologist,   B&B Hospital •    Dr Ranjeet s BaralConsultant cardiologist, GP and Aeromedical Examiner at Ganga Lal, VAYODHA, Advanced Polyclinic and Norvic Hospital •    Dr Prativa Shrestha Das is a Consultant Dermatologist and Aesthetician at Vayodha Hosptial, Balkhu •    Dr Dilip Das is a Dentist at Vayodha Hospital, Balkhu •    Dr Bharat Rawat is Consultant Cardiologist and Head of Cardiology Department at Norvic International Hospital Katmandu, Tripureshwor •    Dr Uttam Kumar Sharma, is Associate Professor of Urology at TU Teaching Hospital and Urologist and Kidney Transplant Surgeon at Chirayu Hospital and Medical Institute, Basundhara, Kathmandu