Cysts are fluid-filled cavities found anywhere in the body, from the head to the toes. They can result from various causes whether spontaneously or after a certain injury that led to a space within the organ. This space is then lined by a certain type of cells and then filled by a fluid. The fluid present within a cyst can be:
- Serum, which is a filtrate of blood
- Blood
- Mucus
- Lymphatic fluid
- Pus, but in the case of pus, it is usually referred to as an abscess.
- And virtually any fluid produced by the body.
Cysts are usually not physiological, and despite how common they are, they usually point towards a disease whether mild or severe. That does not mean that all of them should be treated immediately, and they may be left alone in many cases.
Liver cysts

Our liver is a special organ that is composed of many types of cells and the term “liver cysts” can be ambiguous in that regard. It usually refers to simple liver cysts, but it can also mean any fluid filled space present within the substance of the liver, be it related to the liver itself or not. Generally, cysts of the liver are classified into:
- Simple liver cysts
- Polycystic liver disease
- Hydatid cysts
- Neoplastic cysts
Liver cysts occur in one of every 20 humans, but the incidence is believed to be much higher owing to the fact that most people who have them do not have symptoms, and therefore do not seek medical care. More than 90% of all patients with liver cysts have no symptoms and their cysts may be discovered incidentally during imaging or an abdominal operation for another cause.