Hydatid cysts

A hydatid cyst is like a little water balloon in the liver. It contains clear liquid and the young form of a parasite called a dog tapeworm or Echinococcus.

Also called:echinococcosis, hydatidosis or hydatid disease

The information on this page is for:

Adults and children with hydatid cysts or suspected hydatid cysts.
Anyone wanting to reduce the risk of getting hydatid cysts.
Family, friends, carers, and healthcare professionals.

Hydatid cysts are very rare in the UK. Most people with hydatid cysts will have got the condition overseas. It is more common in parts of Argentina, Peru, East Africa, Central Asia, and China.

Treatment for hydatid cysts can include draining them, taking medicines, or “watch and wait”.

Often the cysts do not cause any issues, but in very rare cases they can burst and cause a severe allergic reaction. This needs immediate medical help.

On this page:

Quick Summary

Hydatid cysts:

are caused by a parasite.
are very rare in the UK.
can also form in other parts of the body, including the lungs.
need a specialist to treat them
can be complicated to treat

Find out more about hydatid cysts on this page.

What causes hydatid cysts?

Young dog tapeworms live in sheep and other farm animals. Dogs can pick them up if they eat raw meat from an animal that had the condition. Once the tapeworms are in a dog, they can become adults and lay eggs. The eggs come out in the dog’s poo.

Humans can accidentally swallow the eggs. For example, by kissing a dog. Or not washing hands properly and then touching the mouth after handling dog poo.

Humans cannot get hydatid cysts from eating meat.

Most cases of hydatid cysts are picked up in rural areas outside Europe. Most cases in the UK link to sheep farming. Particularly in parts of the Outer Hebrides, Herefordshire and mid Wales.

Preventing hydatid cysts:

If you live in or travel to areas with more hydatid cysts, here are some steps to lower your risk.

Wash raw fruits and vegetables before eating them.
Wash hands well after touching a dog, cleaning up dog poo, or touching anything that might have been in contact with dog poo.
Don’t allow dogs to poo near playgrounds, playing fields, or vegetable gardens.
Do not feed dogs raw meat.
Keep dogs away from anywhere that there could be a dead sheep.

If you have a working dog, speak to your vet about ways to protect them.

Symptoms of hydatid cysts

Hydatid cysts start out very small. Most people only get symptoms years after picking them up.

Symptoms will be different for different people. The most common symptoms are:

Tummy pain
Feeling sick (nausea)
Being sick (vomiting)

Some people also have hydatid cysts in their lungs. These can cause:

A cough that lasts a long time (chronic cough)
Feeling short of breath
Chest pain

Tests for hydatid cysts

Hydatid cysts are very rare in the UK. The symptoms are like those found in other liver conditions. So it is normal to have tests to rule out a lot of other things before being diagnosed.

The first tests will likely include a liver blood test and an ultrasound scan. These will give doctors an idea of how the liver is doing and if there are any cysts.

More tests are then needed to confirm exactly what the problem is. This might include an MRI or CT scan, and a blood test to look for antibodies against the parasite.

You can find out more about these tests in the drop-down boxes below.

Travel history

Tell your doctor if you have travelled outside of Europe recently. Particularly if you have been to rural areas in South America, East Africa, Central Asia or China.

Liver blood tests

Anyone with symptoms of liver disease should have a liver blood test. Some doctors still use the old term Liver Function Test (LFT). This test will look at several things in the blood. It cannot diagnose hydatid cysts. But it can give doctors an idea of how the liver is doing. And help to rule out more common liver problems.

Find out more about liver blood tests.

Ultrasound scan

An ultrasound scan is quick and shouldn’t hurt. A wand is placed on the skin. The wand uses sound waves to get a picture of the liver and any cysts that are in it.

find out more about having an ultrasound scan

Antibody test

This is a blood test to look for antibodies that the body has produced against the parasite. This test is not good enough to say for sure if there are hydatid cysts. So it is used alongside other tests to make a diagnosis.

MRI scan

An MRI scan uses magnets and radio waves to build up a picture of the inside of the body. It does not use X-rays and is very good at looking at the soft parts of the body, such as the liver.

An MRI scan usually takes about half an hour. The scanner is a tube. You will lie on a bed that moves into the tube. The scanner can be very loud, so you will be asked to wear headphones.

Find out more about having an MRI scan.

CT scans

A CT scan will take a series of X-rays and use a computer to put them together to make a detailed picture.

A CT scan takes about half an hour. The scanner looks like a ring doughnut. You will lie on a bed that will move in and out of the hole in the middle of the ring.

Find out more about having a CT scan.

Treatment for hydatid cysts

Treating hydatid cysts can be complicated. Anyone diagnosed with hydatid cysts should be referred to a specialist with experience in dealing with hydatid cysts.

The doctor will need to look at the scan results to see how big the cysts are and where they are. They will also want to know if there are cysts anywhere else, such as in the lungs. They will then discuss which type of treatment will be best.

Conversations about different treatment options can be a lot to take in. It is a good idea to take someone with you, make notes, or ask if you can record the appointment on your phone. This will help you remember everything later. You also do not have to decide straight away. You can ask to have some time to think about it. Write down any more questions that you have.

Doctors usually treat hydatid cysts by draining them. But in some cases, doctors use medicines to try and kill the parasite. Or you might be told to “watch and wait”.

Learn more about the different types of treatment in the drop-down boxes below. Every case is different, so talk to the specialist doctor. They can help you find out which treatments might work best.

This information is written for people receiving treatment in the UK. If you’re outside the UK and worried about hydatid cysts, please consult a doctor. Treatment options might differ.

Watch and wait

Some hydatid cysts are inactive. This means there is no parasite growing in them. These cysts do not cause any problems, and they can go away without any treatment. They are sometimes called “quiescent” cysts.

Doctors could recommend leaving these cysts alone. They should give you information about things to look out for. They may also suggest coming back for regular check-ups.

Medicine

Some people are given drugs to try and kill the parasites. This might be called “chemotherapy”. This just means treatment with medicines. It does not mean the treatment is for cancer.

There are several different drugs used to treat hydatid cysts. Doctors might use a mix of different medicines to help them work better.

Medicines might also be given before or after surgery to remove the cysts.

A specialist doctor must prescribe these medicines. They will need to give personal advice for each case. Ask the doctor about the various medicines and their possible side effects.

Draining cysts (aspiration sclerotherapy or PAIR)

Also called PAIR, this stands for Percutaneous Aspiration, Instillation and Reaspiration.

A local anaesthetic and a sedative are given before the procedure. These prevent pain and cause sleepiness. In some cases, a general anaesthetic might be used. The medical team will be able to talk through the different options.

During the procedure a needle will be put through the skin and into the cysts. It will gently suck out the cyst fluid (aspiration). A liquid will then be injected into the cysts. This will cause scarring in the cyst. The scarring pulls the sides of the cyst together to help stop it from filling up again (sclerotherapy). The sclerotherapy liquid will be left to work for a few minutes. Then, it will be sucked back out (reaspiration).

Resection operation

If there are lots of cysts, but they are all in one part of the liver, a resection could cure the condition. This operation removes the part of the liver with the cysts in it.

The liver has an amazing ability to re-grow. If the rest of the liver is healthy, it can return to its normal size in a few months. However, this is a major operation. Talk to the medical team about risks, benefits, and alternatives before deciding to go ahead.

A resection is done using a general anaesthetic. Most people have to stay in hospital for a few days afterwards. This is to make sure they are recovering and have not got an infection.

It is usually difficult to move around and do normal activities for a few weeks after the operation. Before leaving hospital, talk to the doctors. Ask about pain relief and what you should or shouldn’t do while recovering. If possible, have some help lined up for when you get home.

Living with hydatid cysts

Treatment for hydatid cysts can be complicated and can go on for a long time. This can be very worrying. If you are having a hard time, it is important to look after your mental health. We have more information about ways to do this here. You can also find out about our support services further down this page.

There is no evidence that any foods or supplements will help with hydatid cysts. Trying to eat a balanced diet and follow alcohol advice will help to keep the liver working well even if there are cysts.

Useful links
Liver cysts
Benign liver tumours
Liver cancer

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This content was last reviewed: August 2023

Our expert reviewers:

We would like to thank everyone who helped with creating and reviewing this page. Including Dr Abid Suddle, King’s College hospital NHS foundation trust. And all our patient reviewers.

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Everyone’s experience of liver disease will be different. Always talk to your specialist medical team for personal advice.