Most bee stings hurt, swell, and resolve on their own within a few hours. You should be concerned if you notice symptoms spreading beyond the sting site, if breathing becomes difficult, or if swelling and redness keep worsening after the first two days. Those are signs that your body is reacting in a way that needs medical attention.
What a Normal Sting Looks Like
A typical bee sting causes instant, sharp burning pain at the site, followed by a raised welt and localized swelling. For most people, this peaks within the first hour or two and fades completely within a few hours. You might see a small red mark for a day or so, but it shouldn’t be getting worse after that initial window.
Some people have what’s called a moderate reaction: the swelling, redness, and itching around the sting site get progressively worse over the next day or two rather than improving. The area may flush and feel warm. These moderate reactions can last up to seven days but are still considered local, meaning the symptoms stay in the general area of the sting. They’re uncomfortable but not dangerous on their own.
Large Local Reactions
If the swelling around the sting expands to more than about 10 centimeters (roughly 4 inches) across, that’s classified as a large local reaction. This is an allergic response, but it’s a localized one. Your arm might swell from wrist to elbow after a hand sting, for example. It looks alarming, and it can be painful, but most large local reactions resolve within hours to a couple of days without treatment. Over-the-counter antihistamines and ice can help with the discomfort.
A large local reaction does not mean you’ll have a life-threatening reaction next time. However, it’s worth mentioning to your doctor, especially if it happens more than once, since it signals your immune system is sensitized to the venom.
Signs of Anaphylaxis
This is the reaction that genuinely warrants alarm. Anaphylaxis is a whole-body allergic response, and it typically begins within minutes of the sting, though it can sometimes take up to an hour. The key difference from a local reaction is that symptoms show up far from the sting site. Watch for:
- Hives or flushing spreading across skin that wasn’t stung
- Swelling of the tongue, lips, or throat
- Difficulty breathing, wheezing, or a feeling of throat tightness
- Dizziness, lightheadedness, or fainting
- Nausea, vomiting, or stomach cramps
- A rapid or weak pulse
Any combination of these symptoms after a sting is a medical emergency. If you or someone nearby carries an epinephrine auto-injector, use it immediately. International guidelines recommend epinephrine as the first-line treatment for anaphylaxis, and emergency care plans advise using it whenever there’s any doubt about whether anaphylaxis is occurring. If symptoms don’t improve within five minutes of the first dose, a second dose is appropriate, and emergency services should be called right away if they haven’t been already.
Stings in the Mouth or Throat
A sting inside the mouth or on the throat deserves extra caution regardless of whether you have a known allergy. Even a normal local swelling response in these areas can narrow the airway enough to cause breathing problems. If you or your child is stung in the mouth or throat and any difficulty breathing develops, go to the nearest emergency department immediately.
Multiple Stings
A single sting delivers a small amount of venom. Dozens or hundreds of stings, however, can cause a toxic reaction that has nothing to do with allergy. The venom load itself becomes the problem, potentially damaging organs and overwhelming the body. According to the USDA, the average adult can tolerate roughly 10 stings per pound of body weight, which means a healthy adult could theoretically survive over 1,100 stings. But children are far more vulnerable because of their lower body weight, and as few as 500 stings could be fatal for a small child. If someone has been stung many times, especially a child or an older adult, seek emergency care even if no allergic symptoms appear.
Delayed Reactions Days Later
Most people assume that if they’re fine an hour after a sting, they’re in the clear. That’s usually true, but not always. Some people develop delayed allergic reactions that appear anywhere from several hours to two weeks after the sting.
In a study of 10 patients who experienced late-onset reactions, five developed widespread hives 6 to 24 hours after being stung. Two others broke out in hives with throat swelling three days later. Four patients developed a serum sickness-type reaction one to two weeks after the sting, with symptoms like joint pain, fever, and rash. These delayed reactions are uncommon, but they’re worth knowing about. If you develop hives, joint pain, fever, or swelling that appears days after a sting and seems unconnected, the sting may be the cause.
Signs of Infection
A bee sting creates a small puncture wound, and like any break in the skin, it can become infected. Infection doesn’t usually show up immediately. Instead, watch for symptoms that develop or worsen two to three days after the sting: increasing redness that spreads outward from the site, skin that feels hot to the touch, pus or cloudy drainage, worsening pain rather than improving pain, or red streaks radiating from the wound. These are signs of cellulitis, a bacterial skin infection that typically requires antibiotics. A sting that seemed fine initially but starts looking angrier after a few days is more likely infected than allergic.
Who Faces Higher Risk
Certain people are more vulnerable to severe outcomes from bee stings. Anyone who has had a previous anaphylactic reaction to a sting carries significant risk of it happening again and should carry an epinephrine auto-injector. People with underlying heart conditions face an additional concern: the severe drop in blood pressure and cardiovascular stress caused by anaphylaxis can trigger serious cardiac events, including heart attacks in people with existing coronary artery disease or stents.
Young children and older adults also warrant closer monitoring after stings. Children have lower body weight, making them more susceptible to venom toxicity from multiple stings. Older adults are more likely to have cardiovascular conditions that compound the danger of a systemic reaction, and they may not recognize or communicate symptoms as quickly.
If you’ve ever had a reaction that went beyond the sting site, an allergist can perform testing to determine your level of sensitivity and discuss whether venom immunotherapy, a desensitization treatment, makes sense for you.