What is absent kidney? – This refers to non-presence of one or both kidneys at birth. Most people are born with two kidneys, one of which is enough for survival if functioning well. One or both kidneys may be absent at birth. While survival is possible with one kidney if functioning well, it is almost impossible to survive with both kidneys absent. Children with both kidneys absent are either born dead or die within few hours after delivery. 

What are the causes of absent kidney?

This is often due to developmental abnormality of the baby due to genetic problem from either the father or mother. Those who have a parent with only one kidney have up to 50% chance of having one kidney like their parent. Other possible causes of developmental abnormality resulting in baby having one kidney include diabetes in the mother, multiple pregnancy (twins, triplets etc) and some drugs taken in pregnancy. These are factors that interfere with foundation-laying for organ formation early in pregnancy. 

What are the symptoms of absent kidneys?

People with one functioning kidney can live normal life with no symptom. It may never be discovered throughout their lifetime, as discovery is sometimes incidental. However, babies born with no kidney die soon after birth or are even dead before birth. When symptoms occur in those with one kidney, it could be any or a combination of the following:

1. Early onset high blood pressure
2. High protein level in urine
3. Heart defect
4. Clubfoot
5. Developmental abnormality of the uterus and / or vagina
6. Absence of the anus

How is absence of kidney diagnosed?

Since many of those affected by absence of one kidney have no symptoms, in most cases, absence of a kidney is diagnosed by chance when the owner is being investigated for other medical conditions, using ultrasound, CT scan or MRI. However, those with associated anomaly or medical condition, like early development of high blood pressure, may be diagnosed earlier during investigation for those conditions. 

What are the complications of absent kidney?

Babies with absence of both kidneys are either born dead or die within few hours after birth due to difficulty with breathing, as they have poor lung development as a result of lower-than-normal amniotic fluid in the uterus. Children with absence of one kidney may be born prematurely or too small for their age at delivery. They have higher risk of kidney disease than the general population and may develop childhood hypertension. 

How is someone with absent kidney treated?

Persons with one kidney need regular medical checkups in order to prevent complications of other diseases that can affect the only kidney, such as diabetes and hypertension, and treat them on time. Regular urine analysis for protein in urine and kidney function test are very important to ensure adequate kidney function.

How to protect single kidney?

The following steps should be taken by individuals with one kidney to protect the kidney:

1. Adequate water intake
2. Reduce salt and sugar intake
3. Avoid certain pain relievers such as ibuprofen, aspirin, diclofenac and others in that category.
4. Maintain a healthy weight
5. Regular blood pressure checks to detect and treat high blood pressure
6. Regular check of blood sugar to detect and treat diabetes early
7. Avoid high contact sports like football, as these increase the chances of injury to the kidney