Because the symptoms of a cold and strep throat are often quite similar, the best way to know if you have strep throat is to visit a doctor for a strep throat test and physical examination, according to WebMD. A rapid strep test is most commonly used to confirm or rule out the presence of streptococcus bacteria, which causes a strep throat.
If a rapid strep test comes back positive, a diagnosis is confirmed, while a negative diagnosis does not necessarily rule out strep throat when symptoms of it are present, notes WebMD. In some cases, an additional throat culture is needed to confirm diagnosis, and it takes a couple of days to obtain results. Antibiotics are used to treat strep throat and typically alleviate pain and other symptoms within a day or two.
It is important to continue taking the entire course of antibiotics, even if symptoms disappear, to ensure that the bacteria is eradicated. Once someone with strep throat is on antibiotics for 24 hours, he is no longer considered contagious. The most common symptoms of strep throat are similar to a cold but often more severe, according WebMD. Strep throat is most common in children 5 to 15 years old but can also occur in adults.