Polycystic kidney disease (PKD) is a genetic health condition. People who have it develop fluid filled cysts in the kidneys.
These cysts can change the shape and size of the vital organs. This disease is, therefore, a serious condition that can lead to life threatening complications.
In this article, we explain what polycystic kidney disease is and what causes it. We also cover its symptoms, diagnosis, and treatment.
People with PKD develop multiple cysts in their kidneys. These cysts are filled with fluid. Over time, they can make the kidneys larger and change their shape.
The kidneys are fist sized, bean shaped organs. People usually have one on each side of the body underneath the rib cage, attached to the inside of the abdominal wall.
Their job is to filter the blood to remove waste and excess fluid from the body. They ensure that the blood contains a healthy balance of water, salts, and minerals to keep the nerves, muscles, and other bodily tissues working as they should.
The kidneys also make the hormones that the body needs to control blood pressure and produce red blood cells.
PKD interrupts this vital work. As the cysts grow, they can enlarge the organs, change their shape, and even lead to kidney failure. The cysts can also develop in other vital organs, such as the liver.
There are two main types of PKD, which together affect about 500,000 people in the United States:
Autosomal dominant PKD (ADPKD)
Autosomal recessive PKD (ARPKD)
Doctors sometimes call ARPKD infantile PKD, as it affects babies. Worldwide, 1 in 20,000 children have this condition.
A genetic mutation causes PKD. In most cases, this means that the condition passes from parent to child in the DNA.
Sometimes, a person can develop the gene mutation that causes PKD without receiving it from a parent. Scientists call this a spontaneous gene mutation, and it is rare.
PKD affects males and females equally. Age, race, and ethnicity do not seem to influence a person’s chances of having the disorder.
However, people who have a blood relative with PKD are more likely to have the condition than those who do not.
People can live with ADPKD for years without knowing. They usually only receive a diagnosis between 30 and 50 years old if they are experiencing complications.
The symptoms of ADPKD include:
- pain in the side and back
- blood in the urine
ARPKD is much rarer than ADPKD, but doctors may spot it before the baby is born. Signs include the fetus’s kidneys appearing large and a lack of amniotic fluid in the womb, both of which an ultrasound can reveal.
Signs of ARPKD after birth include:
- high blood pressure
- breathing difficulties
- a swollen belly
- vomiting after feeding
- growth problems in the face and limbs
According to the American Kidney Fund, children with ARPKD may not show any symptoms unless they have a severe form of the condition. In these children, symptoms may include:
Doctors currently use three main tests to help them diagnose PKD. These are:
All three are imaging tests that use sound waves or X-rays to look inside the body.
The doctor will check whether any cysts are visible on the kidneys. They will also ask the person about their symptoms and whether anyone in their family has PKD.
Doctors may also use DNA testing to diagnose PKD. To do this, they may ask for a sample of the person’s blood or saliva.
The complications of PKD can include:
As the kidneys enlarge and change shape, they cannot do their job properly. Due to this, harmful waste builds up in the body, and blood pressure rises.
People with kidney failure may retain excess fluid, and their body might not produce enough red blood cells.
According to the PKD Foundation, more than 80% of people with PKD develop cysts in their liver. Among those with PKD, cysts are more common in females than males.
The cysts tend to be very small, meaning that it is rare for them to contribute to liver failure. They can, however, become infected.
The symptoms of an infected liver cyst include fever and a pain in the upper right hand side of the abdomen.
Mitral valve prolapse
When someone has mitral valve prolapse, it means that the valve that separates the top and bottom parts of the heart’s left chamber does not work properly.
Symptoms include heart palpitations and chest pain.
Hernias in the abdomen and groin are more common in people with PKD than in those without the condition.
There is currently no cure for adult PKD, but doctors will work with people to manage the complications and help slow the rate at which the cysts grow.
In some cases, doctors may recommend that people take medication to control their blood pressure.
Depending on the severity of the condition, treatment for ARPKD, or PKD in infants and children, may include:
- growth hormones
- medication to lower blood pressure
- a kidney transplant
- a liver transplant
The outlook for people with PKD depends on the severity of their disease.
Babies born with very severe ARPKD can die within hours or months. About 30% of newborns with ARPKD die before they are 1 month old.
Of those who survive their first month, 82% are still alive at 10 years old.
People with less severe forms of the condition, including those who receive a diagnosis in adulthood, can live for decades without it causing any serious problems.
People can slow the progression of the disease with a healthful diet and lifestyle.
It is important to remember that disease severity varies from person to person.
PKD is a genetic condition that causes fluid filled cysts to grow in the kidneys.
These cysts change the shape and size of these organs and can lead to life threatening complications, including kidney failure.
A doctor may diagnose PKD in the womb or in a baby, child, or adult. In general, a later diagnosis corresponds to a less severe form of the condition.
There is no cure for PKD, but people can take steps to help slow the progression of the disease. These include maintaining a healthful lifestyle and taking medication to control blood pressure.