Why is my son’s one kidney larger than the other?

Q: My 15 years old son is very athletic with good eating habits. He is suffering from headache for the past four months. We consulted both neurologist and nephrologist. The MRI reports and blood tests were normal. Kidney ultra sound diagnosed that one kidney is 1.8 cm larger than the other. And, recently, he has developed high blood pressure (155/75 mmHg). The nephrologist has prescribed medicines and now, his blood pressure has been brought down to 125/65 mmHg. But still he is suffering from regular headaches. Why is his one kidney larger than the other? What other tests should be done to diagnose the disease?

A:Review of history suggests that your son probably has one kidney smaller than the other. Without actual mentioned size of each kidney, it is difficult to comment on the cause. However, unilateral (one side) small sized kidney can rarely present with elevated blood pressure at his age. Usually, unilateral small sized kidney at young age is reflective of a congenital anomaly (inherited at birth) and often doesn't cause any harm to kidney function. Additional tests helpful to assess the kidney function would include urine analysis for increased protein leakage and blood creatinine level to assess the filtering function of the kidneys. Meanwhile, I would advise to go along with the treatment plan for his hypertension laid out by his Nephrologist.