Symptoms of Salmonella

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Salmonella is a common foodborne illness that shows symptoms of watery diarrhea, fever, and abdominal cramps. The symptoms usually last about four to seven days and don't require a trip to the doctor unless seen in an infant or there are signs of a complication. The most common complication is dehydration, while blood infection and invasive salmonella infection is seen rarely. High-risk groups for a more serious infection include infants, young children, the elderly, and people with compromised immune systems.

Salmonella symptoms
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Frequent Symptoms

Symptoms of a salmonella infection, which is called salmonellosis, can begin within six hours and up to four days after you are exposed. The typical incubation period is 12 to 36 hours. You will have symptoms that are common with "stomach flu," which is clinically called gastroenteritis. The typical symptoms usually include:

  • Watery diarrhea: This is the chief symptom and it usually comes on suddenly. At times, diarrhea can also be bloody or have mucus in the stool.
  • Fever: This is almost always seen, and you may have chills.
  • Abdominal pain and abdominal cramps: May be felt.

Less frequent but still common symptoms include nausea, vomiting, loss of appetite, and headache. Watery diarrhea can lead to further symptoms of dehydration if you don't drink enough water to keep up with the loss.

The symptoms may be more severe in young children, older people, or people who have weakened immune systems due to various causes or treatments.

These symptoms usually last about four to seven days and often go away without treatment. However, diarrhea can continue for as long as 10 days. After recovery, you may find that your bowel habits are changed and do not return to normal for several months.


The most frequent complication of salmonella infection is dehydration, and anyone is at risk if diarrhea or vomiting is severe and they are not drinking enough water or an electrolyte solution (Pedialyte or sports drinks like Gatorade) to keep up with the loss. Dehydration is more likely to occur in babies, young children, older adults, and pregnant women. The symptoms are decreased urine production, dry mouth, fewer tears, and sunken eyes. You may also feel tired, dizzy, weak, confused, and have a headache. Severe dehydration can require emergency treatment and hospitalization.

Invasive Salmonella Infection

Invasive salmonella infection occurs in about 8 percent of people who have a confirmed infection. While this sounds alarming, many people do not see their doctor for milder cases and so their cases are never confirmed. The bacteria can enter the bloodstream, where it can then spread to various tissues throughout the body and set up infections. These include meningitis if it infects the brain or spinal cord, osteomyelitis if it infects bones, and septic arthritis if it infects a joint. These infections are serious and can be life-threatening.

Invasive infection is more often seen in the usual high-risk groups of young children, the elderly, and immunocompromised persons.

Antibiotic resistance has been seen for Salmonella species and this can complicate treatment for invasive infections. The doctor may need to use more advanced antibiotics that can cost more and might have more toxic side effects.

Reactive Arthritis

After a salmonella infection, you have a greater risk of developing reactive arthritis, which is also called Reiter's syndrome. The infection triggers inflammation that can result in painful joints (especially the knees, ankles, and feet), irritated eyes, or pain when urinating. This is not common and more often affects people age 20 to 40. It usually will resolve in a year.

When to See a Doctor

You do not need to see your doctor if you have a typical case of salmonella infection that gets better after a few days and you don't have severe symptoms. There is more concern for people in the age risk groups, which include infants, children under age 5, and the elderly. Some pediatricians recommend seeing the doctor any time an infant has symptoms of salmonella. Other groups at risk of a severe infection or invasive infection include people who have a compromised immune system (HIV infection, cancer treatment), have sickle cell disease, have had a splenectomy, or are taking medications that suppress the stomach acid.

If you or your child has symptoms of dehydration, you should see your doctor. Other concerning symptoms that should be checked by your doctor or pediatrician include a high fever, severe or worsening abdominal pain, or bloody stools.

You should get emergency treatment or call 911 if you or your child has these symptoms, which can indicate life-threatening dehydration or the development of an invasive salmonella infection:

  • Difficulty breathing
  • Passing out (fainting)
  • Feel or exhibit confusion
  • Feel very drowsy, have difficulty being woken up
  • Heart rate is rapid
  • Stiff neck or seizure (signs of meningitis)
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Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Salmonella. Symptoms

  2. U.S. National Library of Medicine. MedlinePlus. Salmonella enterocolitis

  3. Centers for Disease Control and Prevention. Salmonella. Information for Healthcare Professionals and Laboratories

  4. Centers for Disease Control and Prevention. Salmonella. Questions and Answers

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