How Salmonella Is Diagnosed

Many of us have eaten foods like eggs, poultry, and vegetables, only to awake in the middle of the night or the next morning with uncomfortable stomach cramps. Since it may be difficult to pinpoint the specific cause of why you feel poorly and are experiencing symptoms, it’s natural that you might feel anxious or scared. But the more you know about the diagnosis, self-checks, evaluations, exams, and procedures related to this condition, the faster you can be on the road to recovery.

Your symptoms may mimic those of the stomach flu but might also be connected to a bacteria called “salmonella,” or “food poisoning,” as some people refer to it.

The good news is that the prognosis for a salmonella infection is very promising. When you have the correct information about how the condition is diagnosed—a combination of symptom analysis and lab tests like a stool test—you’ll be able to choose the best course of action to manage and alleviate your symptoms.

Salmonella diagnosis
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Physical Examination

In most cases, your healthcare provider can gather the necessary information from your medical history, a current list of symptoms, and by completing a physical exam to make a diagnosis.

During the physical exam, the practitioner may assess vital signs and check for evidence of dehydration. He may also palpate the abdomen for pain and tenderness. In pediatric cases of salmonella infections, a healthcare provider may perform a rectal exam to check for the presence of stools containing blood or mucus.

Labs and Tests

There are approximately 1.35 million incidences of salmonella annually in the United States, according to the CDC. Most of these cases originate from various food sources. The symptoms of salmonella infection can be vague and overlap with other conditions. Here’s what you need to know about labs and testing to get an accurate diagnosis.

Stool Testing

If your healthcare provider suspects salmonella may be causing nausea, stomach cramps, diarrhea, fever, and other symptoms, they can order a stool test—that’s the only way to know for sure whether your illness is due to the infection.

There are over 2000 types of the salmonella bacteria, as reported by the Cleveland Clinic.

Your healthcare provider may need to order specific lab tests for your stool sample to identify the type of salmonella responsible for your symptoms. If you need antibiotics, this information will help your practitioner decide which one is the right one for you to take.

Blood Testing

Often, a salmonella infection affects the digestive tract, though, it’s possible for the bacteria to enter the bloodstream. If your healthcare provider believes this has happened, he’ll need to do a blood test to confirm this diagnosis.

Other Tests

When vomiting and diarrhea symptoms become severe, you may require hospitalization. In this event, the healthcare provider may need to order a series of additional labs and tests to stabilize you and get your symptoms under control.

However, for many people, the illness resolves without treatment and may not require any laboratory testing. It should be noted that typical salmonella infections usually last between four and seven days.  


Many patients with acute salmonella infections won’t need to see a healthcare provider. But when they do, the practitioner can decide to treat the infection with medication based on his clinical expertise and the presentation of the illness. As a result, most patients won’t need to undergo any imaging procedures like X-rays, ultrasounds, or CT scans.  

Self-Checks/At-Home Testing 

There are a couple of at-home options you can use to help you determine whether you’ve potentially been exposed to salmonella. If your symptoms are severe, this information can help you discuss available treatment choices with your healthcare provider.

Test Kits

A quick online search will yield results for multiple, at-home kits that check for the presence of salmonella. These kits purport to be easy-to-use and deliver reliable results. However, most of the kits test things like food, water, and your environment, so they won’t offer you a clear picture of what’s going on inside of your body. Plus, there is limited data on the reliability of these test kits.

Additionally, some of the tests contain multi-step instructions to follow, so you might not feel like channeling your inner chemist when you’re sick.

Sometimes, the kits can take up to 48 hours to yield results; you shouldn’t wait to seek medical attention if your symptoms are severe.

Check the Centers for Disease Control and Prevention (CDC) Website

When there’s an outbreak of foodborne diseases like salmonella, public health and regulatory officials work rapidly to identify the source and take preventive steps so that others don’t get sick.

When the CDC communicates with the public about an outbreak, they post a web announcement on the CDC Foodborne Outbreaks website.

Here, you can find information about the types of foods that have been contaminated in the outbreak, the number of people that have gotten sick per state, the signs and symptoms of the foodborne disease, and more.

If you suspect you may have salmonella from an outbreak of foodborne disease, contact your healthcare provider so that you can receive any medical care you may need.

Differential Diagnoses

The set of symptoms associated with a salmonella infection may differ from person to person, and the symptoms can overlap with conditions like Crohn's disease or appendicitis. If the healthcare provider thinks your illness may be due to something other than salmonella, she’ll need to gather more information to make appropriate recommendations regarding your treatment and plan of care.

It’s important to know that dehydration from vomiting and diarrhea is a major concern with salmonella, so make sure you stay hydrated.

If you find your symptoms haven’t cleared up within a few days of their onset, it’s a good idea to make an appointment with your healthcare provider to determine the best approach to caring for your health.

Frequently Asked Questions

  • How is Salmonella typhi diagnosed?

    Salmonella typhi, the Salmonella bacterium that causes typhoid fever, typically is diagnosed based on symptoms and blood, urine, or stool tests. Symptoms can include headache, appetite loss, constipation, and fatigue, followed by a very high fever, stomach pain, nosebleeds, rose-colored spots on the chest, diarrhea, and a decrease in pulse rate.

  • What illnesses do healthcare providers need to rule out in order to diagnose Salmonella poisoning?

    A variety of diseases and conditions can be mistaken for Salmonella poisoning, clinically known as Salmonella gastroenteritis. Infection with another food-borne bacterium such as Escheria coli (E. coli) is a common one. Others include stomach flu, mononucleosis, tuberculosis, endocarditis (an infection of the heart), encephalitis, and malaria.

  • How long does it take to find out if I have Salmonella poisoning?

    It can take three to five days to get the results of a traditional Salmonella lab test based on a blood, urine, or stool sample. There also are rapid tests available that can yield results within 48 hours.

  • What can happen if Salmonella poisoning isn't treated?

    Typically the symptoms will resolve in four to seven days without treatment (other than rest and drinking lots of fluids). It's only in rare cases that a Salmonella infection causes complications that require treatment, such as intravenous fluids for severe diarrhea or a hospital stay or antibiotic treatment if the infection gets into the bloodstream.

6 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.

  2. Humphries RM, Linscott AJ. Laboratory Diagnosis of Bacterial GastroenteritisClin Microbiol Rev. 2015;28(1):3-31. doi:10.1128/CMR.00073-14

  3. Centers for Disease Control and Prevention. Foodborne Outbreaks.

  4. Centers for Disease Control and Prevention. Typhoid fever and paratyphoid fever. Questions and answers.

  5. Ajmera A, Shabbir N. Salmonella. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. 

  6. Cleveland Clinic. Salmonella.

Additional Reading

By Jenny Lelwica Buttaccio, OTR/L
Jenny Lelwica Buttaccio, OTR/L, is a licensed occupational therapist and advocate for patients with Lyme disease.