You should worry about a spider bite and seek medical care in the following situations:
- If you are bitten by a known venomous spider such as a black widow or brown recluse, get medical help immediately.
- If the bite produces severe symptoms like:
- Severe pain at the bite site
- Muscle cramps spreading from the bite site
- Difficulty breathing or swallowing
- Swelling of the face, mouth, throat, or eyes
- Fever, chills, or body aches
- Enlarged or worsening wound with redness streaking
- Blisters, necrosis (tissue death), or ulceration at the bite site
- Allergic reactions such as hives, fast heart rate, loss of consciousness, or anaphylaxis
- If symptoms worsen over time rather than improve within a few days.
- If you suspect infection signs like pus, spreading redness, swollen glands, or increasing pain.
- If you experience severe systemic symptoms such as nausea, vomiting, weakness, or confusion.
Immediate emergency care is advised when these symptoms are present, especially for venomous spider bites or severe allergic reactions. If you can, capturing the spider safely to help identify it can assist medical professionals in treatment. For most common, non-venomous spider bites, mild redness, swelling, and itching are typical and usually resolve on their own within a few days without complications. In general, monitor the bite site closely and seek medical attention if you notice worsening symptoms or systemic signs of a severe reaction. This guidance is based on symptoms of concern from sources including KidsHealth, Healthline, Mayo Clinic, and other medical authorities as of 2025.
