When you throw up, you lose not only fluids, but electrolytes. It's important to hydrate after vomiting — with both fluids and electrolytes — to make sure you don't become more ill. In certain cases, like severe vomiting, you may need medical care to rehydrate properly.
Complications From Vomiting
You also lose electrolytes with these fluids. According to Nithin Natwa, MD, a sports medicine physician with the Henry Ford Health System in Michigan, "you do lose electrolytes after throwing up ... specifically, sodium and chloride." This usually leads to metabolic alkalosis, a condition that occurs when there is too much base (alkali) in the body fluids, explains the U.S. National Library of Medicine (NLM).
But, if vomiting is so severe that it causes dehydration, you can develop metabolic acidosis, with symptoms that include heavy, rapid breathing, confusion and fatigue, notes the NLM. Untreated metabolic acidosis can even lead to shock or death.
An April 2014 review article in Comprehensive Physiology notes that potassium is another electrolyte that should be replenished after severe episodes of fluid loss.
"With that said, as long as the vomiting is mild, your body will adapt through the respiratory system," says Dr. Natwa.
However, when vomiting is more severe, it is important to rehydrate properly to correct your fluid and electrolyte levels and prevent medical complications. Vomiting can lead to dehydration, and dehydration can lead to severe complications, so it is important to rehydrate. According to the NLM, some symptoms of dehydration in adults can include:
- Dry mouth
- Dark-colored urine
- Feeling very thirsty
In addition to dehydration, some of the other severe symptoms that may accompany vomiting, according to the Cleveland Clinic, include:
- Blood in vomit (looks like black bits, similar to coffee grounds)
- Black, tarry bowel movements
- Muscle cramps
- Fever (101 degrees Fahrenheit or higher)
If you experience these symptoms along with throwing up, you should seek medical help.
How to Rehydrate at Home
Seeking medical care is usually not necessary, Dr. Natwa says, "unless you have been vomiting multiple times."
However, it is important to drink fluid after vomiting to compensate for fluid losses. Ideally, this fluid should also contain some electrolytes to replenish what you've lost. According to the Comprehensive Physiology article, you should look for a rehydration drink that contains sodium, chloride and potassium.
The best option to rehydrate at home, according to Dr. Natwa, is a "slow, measured intake of water or unsweetened sports drink, even if you don't feel thirsty."
According to the Cleveland Clinic, clear fluids like water, broth or ginger ale are the best drinks for rehydration after vomiting. Until you are fully recovered, you should avoid excess sugar to limit your risk of becoming dehydrated. You should also limit fatty foods and avoid strong smells, as they may trigger nausea and lead to more vomiting.
When to Seek Medical Care
If you are vomiting excessively or for two or more days, you may need to seek medical care, according to the Cleveland Clinic. If your vomiting is accompanied by high fever, severe headaches or any symptoms of dehydration — or if there is blood in your vomit — you should seek medical care immediately.
It is important for a health professional to identify the root cause of your vomiting so that it can be properly treated.
According to Dr. Natwa, the best medical treatments for vomiting include intravenous (IV) fluids and anti-nausea medication. Another good rule of thumb for when it's time to see a doctor is whether you are able to keep fluids down after throwing up. "If you are unable to keep fluid down," Dr. Natwa says, "it is best to see a physician for further evaluation."
Is This an Emergency?
- Cleveland Clinic: “Vomiting 101: Why You Throw Up and the Best Way to Recover”
- Comprehensive Physiology: “Optimal Composition of Fluid-Replacement Beverages”
- Nithin Natwa, MD, sports medicine physician with the Henry Ford Health System, Michigan
- U.S. National Library of Medicine: “Metabolic Acidosis”
- U.S. National Library of Medicine: “Metabolic Alkalosis”
- U.S. National Library of Medicine: “Dehydration”