More than 160,000 different kinds of insects exist in the United States. Most of them live peacefully alongside humans — and many are beneficial, including those that pollinate plants that produce fruits, vegetables, nuts and flowers.

But some bugs also bite or sting, causing itching, pain and other symptoms. These symptoms can usually be treated at home. However, some people are allergic to bee stings and insect bites and can go into anaphylactic shock, which is a medical emergency. Even if you're not allergic, some bites may require medical attention.

How do you know when to be concerned about bug bites and stings? Here's what you need to know.

Determining if a reaction is dangerous

If you have an allergic reaction, a bug bite can quickly become a medical emergency. Allergic reactions can happen to anyone, even if you've had bug bites or stings in the past with no problem. Allergic reactions are more common with stings than bites, especially if you're stung more than once. Symptoms usually start within 30 minutes of the bite or sting.

Any of these symptoms may require a call to 911 or a trip to the nearest emergency room:

  • Difficulty breathing
  • Swelling in the face, lips, tongue or throat
  • Racing heartbeat
  • Rash or hives
  • Stomach pain or vomiting
  • Fainting or dizziness

Spotting signs of tick-borne and mosquito-borne infection

Most mosquito bites just cause itching, but some can spread diseases like Zika and West Nile virus, as well as other illnesses. Ticks in the Northeast and Upper Midwest are more likely to cause diseases like Lyme disease, Rocky Mountain spotted fever and even alpha-gal syndrome, a condition in which the person becomes allergic to a protein found in meat and dairy products.

Keep an eye on the bite. Even if it doesn't look bad at first, watch for signs and symptoms that might mean the bug has passed along a disease, including:

  • Fever and chills
  • Headache and muscle aches
  • Fatigue
  • Rash

Different diseases can cause different rashes. Lyme disease or southern tick-associated rash illnesses can cause a "bull's-eye" rash, while Rocky Mountain spotted fever causes a splotchy rash. Not everyone who develops a tick-borne disease will notice the rash — or even the tick bite.

Scratching bug bites can also lead to infection, which may need medical attention. Bites that don't heal properly can leave scars. If you have trouble controlling the itch with at-home methods, talk to your doctor.

Treating bug bites and stings at home

You can treat most bug bites at home. Most mosquito bites cause an itchy red bump that can remain on the skin for a few days. A yellow jacket, bee or wasp sting can cause immediate pain, itching and swelling. Here's how to treat the bite or sting at home:

  • If the tick is still attached, remove it with tweezers. Grasp it with the tweezers as close to the skin as you can. Pull it gently and steadily, trying to get as much of the bug and mouth parts as you can. Dispose of the tick by putting it in a sealed container, wrapping it in tape or flushing it down the toilet.
  • If a bee or wasp has left a stinger, remove it by scraping it with your fingernail. Never use tweezers since that can release more venom.
  • Wash the area with soap and water. To reduce swelling and ease pain, wrap ice in a washcloth and hold it on the sting for 10 minutes at a time.
  • Make a paste from baking soda and water and spread it on the bite to ease any itching. Taking an antihistamine or applying anti-itch cream can also help.

Preventing bug bites and stings

Most bug bites are more of an annoyance than a danger, but it makes sense to protect yourself, especially in areas where insects are most active or prevalent. That includes dense woods, open meadows with long grass or around water or swampy areas. Mosquitos and flies are usually most active around dawn or dusk. Here's how you can protect yourself:

  • Cover exposed skin with long sleeves, long pants and closed-toe shoes.
  • Apply an insect repellent that contains 20% to 30% DEET on your clothing or exposed skin.
  • Choose light-colored fabrics to help you spot any insect that lands on you.
  • Consider wearing a hat with a net to protect yourself in areas with black flies or mosquitos.

Knowing which insects are in your area can also help you protect yourself and identify bug bites that require more immediate treatment. In the northern United States, especially in areas with streams and lakes, you're likely to run into black flies that can swarm and bite. In warmer states, a bad case of chigger bites can definitely take the fun out of a walk through a meadow. Knowing what to expect can help you know when to be concerned about bug bites and stings.