What Is an Insulinoma?
An insulinoma is a rare tumor that develops in the pancreas. These tumors make extra insulin, a hormone that helps control blood sugar. When too much insulin is released, blood sugar levels can drop too low.
The exact cause of insulinomas is not fully understood. Some people may have a higher risk because of inherited genetic conditions such as multiple endocrine neoplasia type 1 (MEN1).
Most insulinomas are not cancerous. Even though they are usually small, they can cause noticeable symptoms because of repeated episodes of low blood sugar.
Symptoms
Low blood sugar caused by an insulinoma can affect both the body and brain. Symptoms may come and go and are often more noticeable when you have not eaten for several hours or after physical activity.
Common symptoms include:
- Sweating
- Shakiness
- Weakness or fatigue
- Fast heartbeat
- Hunger
- Confusion
- Blurred or double vision
- Dizziness or fainting
In severe cases, very low blood sugar can lead to seizures or loss of consciousness.
How Is It Diagnosed?
Your healthcare provider will review your symptoms, medical history, and blood sugar patterns. Because insulinomas are rare, diagnosis can sometimes take time.
Blood tests are used to measure glucose and insulin levels, especially during episodes of low blood sugar. Some people may need a supervised fasting test so providers can safely monitor how the body responds over time.
Imaging tests can help locate the tumor and guide treatment planning. These may include:
- CT scan
- MRI
- Ultrasound
- Endoscopic ultrasound
In some cases, additional specialized testing may be needed to pinpoint where excess insulin is being produced.
How Is It Treated?
Surgery is the most common treatment for an insulinoma. Removing the tumor often corrects the low blood sugar problem completely. Many tumors can be removed using minimally invasive techniques with smaller incisions and shorter recovery times.
If surgery is not immediately possible, treatment may focus on controlling blood sugar levels. Your provider may recommend:
- Eating smaller meals more often
- Medicines that help reduce insulin effects
- IV glucose for severe low blood sugar episodes
Rare cancerous insulinomas may require additional care, including chemotherapy or other therapies to slow tumor growth.
Most people recover well after treatment, and symptoms usually improve once blood sugar levels return to normal.
