Polycystic kidney disease: symptoms, diagnosis and treatment

1What is polycystic kidney disease?

Autosomal dominant polycystic kidney disease (ADPKD) is an inherited condition in which many small fluid-filled sacs (cysts) form in both kidneys and slowly grow over the years. People are born with it, but it usually causes no obvious problems until the cysts are large enough to affect kidney function. According to the NHS, this most often happens between 30 and 40 years of age, although symptoms can start at any point between 30 and 60.

A rarer form, autosomal recessive PKD (ARPKD), only occurs when both parents carry the faulty gene. It usually shows in childhood, sometimes before birth.

2How is it inherited?

A faulty gene disrupts the normal development of kidney cells. The two known genes are PKD1 and PKD2. According to the NHS and the US NIDDK, PKD1 disease tends to be more severe.

• According to the NHS, each child of a parent with ADPKD has a 1 in 2 (50%) chance of inheriting the faulty gene.
• Sometimes the gene change arises for the first time in a person, who can then pass it on.

🩺Symptoms

According to the NHS, problems usually start between 30 and 60 years of age. The main symptoms are:

• Pain in the tummy, side or lower back, often the first noticeable sign.
• Blood in the urine (haematuria): a common early symptom that may clear by itself but should always be checked. Read more about blood in urine and its other causes.
• High blood pressure: often has no symptoms and is found at routine checks.
• Kidney stones: intense pain in the back or side, sometimes the groin, with nausea or blood in the urine.
• Urinary tract infections: stinging and frequent urination, or fever and shivering if the infection reaches the kidneys.

NIDDK adds that headaches are also common.

4How it differs from simple kidney cysts

According to NIDDK, simple kidney cysts were found in about 1 in 10 people in one large study, and in nearly 1 in 5 people aged 50 and over.

🔬How is polycystic kidney disease diagnosed?

The doctor asks about symptoms and family history, checks blood pressure, and arranges a urine test for blood or protein and blood tests to estimate how well the kidneys filter. As described by the NHS and NIDDK, tests include:

• Ultrasound: a painless scan that shows cysts in the kidneys or liver. See our page on urology ultrasound.
• CT or MRI: more detailed images; MRI can measure kidney size and track how the disease progresses.
• Genetic testing: from a blood or saliva sample. The NHS says it is not done routinely, only in special circumstances, and it can be negative in 10% of people who have ADPKD.

The NHS describes screening relatives without symptoms as a decision with pros and cons: it can find high blood pressure early so it can be treated, but it may cause anxiety because nothing yet stops the disease developing. Discuss it with your doctor and family before testing yourself or your children.

6Possible complications

• Declining kidney function: the disease can lead to chronic kidney disease. According to the NHS, on average about half of people need treatment for kidney failure by age 60, though this varies widely.
• Heart and blood vessel disease, linked to high blood pressure.
• Liver cysts: the most common complication outside the kidneys according to NIDDK; they rarely affect liver function.
• Brain aneurysm: according to the NHS, about 10% of people with ADPKD develop one. Most cause no symptoms, but a rupture is an emergency.
• Cyst infection or bleeding, kidney stones and repeated urinary infections.

💊Treatment and follow-up: nephrologist and urologist roles

There is no cure yet, but regular follow-up reduces complications. According to the NHS, a kidney specialist (nephrologist) usually draws up the long-term plan, which may include:

• Controlling blood pressure with medicines chosen by the doctor, and cutting salt (the NHS advises under 6g a day).
• A medicine recommended by NICE for selected adults to slow cyst growth, with close liver monitoring; the nephrologist decides whether it is suitable.
• Avoiding some painkillers that may harm the kidneys unless a doctor advises otherwise, and avoiding contact sports that could injure the kidneys.
• If the kidneys fail: dialysis or a kidney transplant.

A urologist assesses pain and blood in the urine and treats kidney stones; the NHS notes that larger stones may need shock wave treatment or a ureteroscope. Urologists also help treat urinary infections and infected cysts that may need draining, and refer to a nephrologist when needed.

⏰When to seek urgent care

See a doctor promptly if you notice blood in your urine or symptoms of a urinary infection, because infection can spread to the kidney cysts. Seek urgent care for:

• Severe pain in the side or back like kidney stone pain, especially with fever or vomiting.
• Fever and shivering with kidney pain.
• A persistent headache with blurred vision, nosebleeds or shortness of breath, which may mean very high blood pressure.

Call an ambulance immediately for a sudden, extremely severe headache, stiff neck, vomiting, sensitivity to light, confusion, weakness on one side, or loss of consciousness. According to the NHS, these can be signs of bleeding on the brain from an aneurysm.

❓Frequently asked questions

10Sources

1. Autosomal dominant polycystic kidney disease (ADPKD) – NHS
2. Symptoms – Autosomal dominant polycystic kidney disease (ADPKD) – NHS
3. Diagnosis – Autosomal dominant polycystic kidney disease (ADPKD) – NHS
4. Treatment – Autosomal dominant polycystic kidney disease (ADPKD) – NHS
5. Complications – Autosomal dominant polycystic kidney disease (ADPKD) – NHS
6. Autosomal Dominant Polycystic Kidney Disease – NIDDK
7. Simple Kidney Cysts – NIDDK