Medically reviewed by Saurabh Sethi, M.D., MPH — Written by Jill Seladi-Schulman, Ph.D. on May 11, 2020

Your stomach’s job is to help digest the food you eat. One way that it does this is through the use of stomach acid, also known as gastric acid. The main component of stomach acid is hydrochloric acid.

The lining of your stomach naturally secretes stomach acid. This secretion is controlled both by hormones and your nervous system.

Sometimes your stomach can produce too much stomach acid, which can lead to several unpleasant symptoms.

What can cause high stomach acid?

There are several conditions that can lead to high stomach acid. Often, these conditions lead to an overproduction of the hormone gastrin. Gastrin is a hormone that tells your stomach to produce more stomach acid.

Some of the most common causes include:

  • Rebound acid hypersecretion: H2 blockers are a type of medication that can decrease stomach acid. Sometimes, people coming off of this medication can have an increase in stomach acid. There’s evidence that this can also happen after coming off of proton pump inhibitors (PPIs), although this is controversialTrusted Source.
  • Zollinger-Ellison syndrome: With this rare condition, tumors called gastrinomas form in your pancreas and small intestine. Gastrinomas produce high levels of gastrin, which causes increased stomach acid.
  • Helicobacter pylori infection: H. pylori is a type of bacteria that can colonize the stomach and cause ulcers. Some people with an H. pylori infection may also have high stomach acid.
  • Gastric outlet obstruction: When the path leading from the stomach to the small intestine is blocked, it can result in increased stomach acid.
  • Chronic kidney failure: In some rare cases, people with kidney failure or those undergoing dialysis may produce high levels of gastrin, leading to increased production of stomach acid.

It’s also important to note that sometimes a specific cause of high stomach acid can’t be identified. When the cause of a condition cannot be determined, it’s referred to as idiopathic.