Generally, food poisoning causes some combination of nausea, vomiting, and diarrhea that may or may not be bloody, sometimes with other symptoms.
After eating tainted food, abdominal cramps, diarrhea, and vomiting, can start as early as one hour in the case of staph and as late as 10 days in the case of campylobacter. It may take even longer to develop symptoms from parasite infections such as Giardia. Symptoms can last from one day up to a couple of months or longer, depending on the type of infection.
Vomiting, diarrhea, sweating, dizziness, tearing in the eyes, excessive salivation, mental confusion, and stomach pain may be symptoms of chemical or toxin food poisoning such as that from poisonous mushrooms.
Partial loss of speech or vision, muscle weakness, difficulty swallowing, dry mouth, muscle paralysis from the head down through the body, and vomiting may indicate botulism, a severe but very rare type of bacterial food poisoning.
Any signs of dehydration such as dry mouth, decreased urination, dizziness, or sunken eyes
Any diarrhea in a newborn or infant
Diarrhea that lasts longer than 2 days (one day in a child) or is severe
Severe abdominal pain or vomiting
Fever of 102°F or higher (or a rectal temperature of 100.4°F in baby younger than 3 months of age)
Stools that are black, tarry, or bloody
You recognize symptoms of chemical or toxin food poisoning, such as vomiting, diarrhea, sweating, dizziness, tearing in the eyes, excessive salivation, mental confusion, and stomach pain, beginning about 30 minutes after eating contaminated food. You need immediate medical treatment to help avoid potential damage to one or more of your vital organs.
Call 911 if you recognize any symptoms of botulism, such as partial loss of speech or vision, muscle weakness, difficulty swallowing, dry mouth, muscle paralysis from the head down through the body, and vomiting. You need immediate medical treatment for this potentially life-threatening illness.