When you have strep throat, you usually don’t have a runny nose or cough. Anyone can get strep throat, but children between the ages of 5 and 15 tend to get it most often. In adults, only 10% of sore throats are caused by strep, says Linder. To find out if you have it, your doctor may swab the back of your throat to do a rapid strep test. If it's positive, your doctor will prescribe an antibiotic.