Most spider bites can be safely treated at home with basic first aid: clean the wound, apply a cold compress, and keep the area elevated. The vast majority of spider bites come from species whose venom causes nothing more than mild pain, redness, and swelling that resolves within a few days. Knowing the right steps, what to avoid, and when to seek help covers nearly everything you need.
Immediate First Aid Steps
Start by washing the bite with mild soap and water. This is the single most important thing you can do, since bacterial infection from a dirty wound is a bigger risk than the venom itself for most spider species. Pat it dry with a clean towel.
Next, apply a cool compress over the bite for 15 minutes at a time, once per hour. A clean cloth dampened with cold water works fine, or you can wrap a handful of ice in a thin towel. Don’t press ice directly against your skin. The cold constricts blood vessels near the surface, which slows swelling and dulls pain.
If the bite is on your hand, arm, foot, or leg, keep that limb elevated above the level of your heart when you’re sitting or lying down. Elevation helps fluid drain away from the area and limits how much the tissue swells during the first 24 to 48 hours.
Managing Pain and Itching
An over-the-counter pain reliever like ibuprofen or acetaminophen handles most of the discomfort from a typical spider bite. Ibuprofen also reduces inflammation, so it pulls double duty. For itching, an oral antihistamine (the kind you’d take for allergies) can take the edge off. A dab of hydrocortisone cream on the bite works well for localized itch and mild swelling.
Resist the urge to scratch. Broken skin around the bite site invites bacteria in and dramatically increases the chance of a secondary infection.
What Not to Do
Some popular home remedies do more harm than good. Don’t apply heat or a warm compress to a fresh spider bite. Heat increases blood flow to the area, which can worsen swelling and speed the spread of venom through surrounding tissue. Don’t try to cut the bite open, squeeze it, or suction the venom out. These methods don’t remove meaningful amounts of venom and create additional wounds that are prone to infection.
Avoid applying a tourniquet or tightly wrapping the limb above the bite. Unlike certain snakebites, spider bites don’t benefit from restricted blood flow, and a tourniquet can cause serious tissue damage on its own. Stick to the basics: clean, cool, and elevate.
How to Tell If a Bite Is More Serious
Most spider bites look like a small red bump, similar to a mosquito bite or a bee sting without the stinger. Two types of spiders found in the U.S. demand extra caution: the black widow and the brown recluse.
Black widow bites often show two small puncture marks. Pain tends to start at the bite and radiate outward within an hour, sometimes causing severe muscle cramping in the abdomen or back. Brown recluse bites typically begin with a stinging sensation and localized pain. A small white blister usually forms at the site, and over the following hours or days, the surrounding skin can turn reddish to purplish. In some cases, the venom destroys skin tissue, creating a growing wound that looks worse before it looks better. The majority of brown recluse bites heal within three weeks, but some progress to deeper tissue damage that needs medical care.
If you didn’t see the spider, watch your symptoms. The bite itself often looks identical across species in the first few hours, so your body’s overall reaction tells the real story.
Signs You Need Medical Help
Certain symptoms after a spider bite signal that home treatment isn’t enough. Get medical attention if you experience any of the following:
- Difficulty breathing or tightness in your chest
- Severe muscle pain, cramping, or weakness that spreads beyond the bite area
- Heart palpitations or a racing pulse
- Nausea and vomiting
- Severe headache or vision changes
- Signs of infection: increasing redness that spreads outward, skin that feels hot to the touch, fever, or cloudy fluid draining from the wound
Children under 16 and adults over 60 are at higher risk from venomous bites, particularly black widow bites, and may need hospital treatment for breathing problems, blood pressure changes, or severe muscle cramping.
Watching for Infection Over the Next Few Days
Even a harmless spider bite can turn into a skin infection called cellulitis if bacteria get into the wound. The warning signs are skin that becomes increasingly painful, hot, and swollen over the days following the bite. The area may look red (though on darker skin tones, the color change can be subtler, appearing more purple or simply feeling warmer than surrounding skin). Blistering and flu-like symptoms, including swollen glands, are also red flags.
If infection spreads, you may develop a fast heartbeat, chills, dizziness, or confusion. At that point, the situation has become urgent. Cellulitis that goes untreated can move into the bloodstream, muscles, or bones.
Check the bite twice a day. A simple trick is to draw a line around the edge of any redness with a pen. If the redness moves past that line over the next 12 to 24 hours, infection is spreading and you should get it evaluated.
Tetanus and Spider Bites
Spider bites create a puncture wound, which can carry a small risk of tetanus. You don’t need a booster if you’ve completed your primary tetanus vaccine series and your last shot was less than five years ago. If it’s been five or more years since your last tetanus vaccine and the wound looks dirty or significant, a booster is recommended. If you’re unsure of your vaccination history or never completed the full series, getting a tetanus shot is a good idea regardless of how the wound looks.
Typical Healing Timeline
A bite from a common house spider usually improves within a few days. The redness and swelling peak around 24 to 48 hours, then gradually fade. You might have a small, itchy bump for a week or so.
Brown recluse bites take longer. Most heal within about three weeks, though the wound can look alarming during that time as the body works to clear damaged tissue. If the area around the bite keeps growing, pain increases, or the wound starts draining cloudy fluid, those are signs of infection or progressing tissue damage that needs professional care. With a venomous bite, checking in with a healthcare provider early gives you a baseline so they can track changes if the wound doesn’t follow a normal healing path.