If you experience difficulty breathing after a bug bite or sting, it could be due to a severe allergic reaction, and according to the Mayo Clinic, you should go to the emergency room.This reaction is particularly common with bee stings.Difficulty breathing can be a sign that you have gone into anaphylactic shock, and according to WebMD, if you have a known, severe bee-sting allergy you should carry around any prescribed epinephrine injections at all times.According to the Mayo Clinic, vomiting and body aches can be symptoms of the West Nile virus. Not everyone who contracts the diseases shows symptoms, but you may want to seek immediate medical attention if your reaction to a bite includes things like a high fever, severe headaches, or muscle weakness. According to WebMD, severe abdominal cramping can also be a sign of a black-widow bite. If you think you could've been bitten by a black-widow spider, you may want to see a doctor to review if treatment is necessary.That said, per WebMD, black-widow bites can be dangerous for young children so if you suspect a child has been bit by one, help them seek out immediate medical attention. In addition, nausea, vomiting, and stomach pain can be symptoms of anaphylactic shock, according to WebMD. If you suspect this may be the case with your bite, seek out immediate medical attention. Swelling of the lips, throat, or eyelids is also a common sign of an allergic reaction to a bee sting. WebMD lists it as a symptom of anaphylactic shock and recommends seeking immediate medical attention if you are experiencing these symptoms.According to Healthline, if you are experiencing swelling of the eye after a bug bite, you may want to to see a doctor — especially if the swelling is causing any pain, vision distortion, or floaters.These kinds of symptoms could indicate either anaphylactic shock or a toxic reaction to a bite or sting. The Mayo Clinic recommends going to the emergency room if these symptoms are severe. If you develop a red, target- or doughnut-shaped rash around the site of a tick bite you may have contracted Lyme disease.Dermatologist Margaret E. Parsons of the American Academy of Dermatology recommends seeking medical treatment so you can be prescribed the proper antibiotics to better treat and manage the disease. According to the Mayo Clinic, you should still visit your doctor even if the rash or other symptoms seem to disappear. A rapid heartbeat is another symptom of anaphylactic shock and requires emergency medical attention.Mayo Clinic recommends going to the ER if your heartbeat is racing after a bug bite or sting.If hives persist after getting stung or bitten, the Mayo Clinic recommends going to the emergency room for immediate treatment as it can also be a sign of a severe allergic reaction.In addition, per Medical News Today, you may want to seek out medical attention if you notice a blotchy rash on your body since that could also be indicative of a severe allergic reaction.As with nausea, headaches and fever can be symptoms of the West Nile virus, according to the World Health Organization.If high fever and severe headaches persist after a mosquito bite, seek medical care, especially if you are over the age of 50 or immunocompromised and have a higher risk of getting seriously ill from the virus. According to WebMD, Lyme disease symptoms also include headaches, fever, and chills, as well as other flu-like symptoms.If left untreated, Lyme disease can cause short-term memory loss or heart problems, so seek medical help as soon as possible. Read more:11 myths about lice you need to stop believingA woman thought she may have had a simple bug bite in her groin — but it was really a baby fly burrowed into her skin5 animals that could survive the apocalypseStink bugs are swarming parts of Utah: 'Never seen anything like this'