Ticks are small arachnids related to spiders. They attach to your skin and feed on blood.
A tick bite may cause a temporary red spot or itching. If an infected tick bites you, it can transmit bacteria, viruses, or parasites that cause tick-borne diseases.
Ticks do not fly or jump. They wait on grasses, shrubs, or leaf litter, then climb onto you when you brush past.
Risk depends on the tick species, location, attachment time, and whether the tick carries a pathogen. Many tickborne diseases share symptoms, so your healthcare professional may consider your symptoms, travel or outdoor exposure, and testing together, as noted by the Centers for Disease Control and Prevention’s tick guidance.
How Ticks Attach and Affect People
Ticks grasp your skin, cut into its surface, and insert a feeding tube. Their saliva may numb the area and help them remain attached while pathogens enter during feeding.
What an Attached or Engorged Tick Looks Like
An attached tick may look like a tiny dark seed, raised bump, or small brown, gray, or reddish insect. Its mouthparts remain embedded in your skin, while its body can swell as it feeds.
An engorged tick may become rounder and much larger than it was before feeding. Ticks vary greatly in size.
Nymphs can be smaller than a sesame seed, making them easy to miss around your hairline, armpits, groin, waist, or behind your knees.
Why Tick Saliva Can Cause Skin Reactions
Tick saliva contains substances that help the tick feed and stay attached. Those substances can cause localized redness, itching, swelling, or tenderness without causing an infection.
Saliva from some ticks can also contain toxins. Rarely, an attached tick can cause tick paralysis, which may produce weakness that gradually moves upward through your body.
Removing the tick typically allows movement to return. Progressive weakness requires urgent medical attention.
Hard Ticks and Soft Ticks
Most human bites in the United States come from hard ticks, classified in the family Ixodidae. They have a firm outer covering and a visible shield called the scutum.
Their feeding can last from hours to several days. Soft ticks, classified in the family Argasidae, have a flexible body and lack the prominent scutum seen in hard ticks.
They often feed quickly and may be associated with rodent-infested buildings, caves, or rustic sleeping areas. Either group can carry pathogens, including bacteria, viruses, or parasites.
Tick Bite Symptoms and Warning Signs
A bite may leave a small itchy or discolored area that improves within a few days. Fever, chills, headache, fatigue, muscle aches, rash, or other new symptoms after exposure deserve medical attention.
Normal Local Reactions Versus Allergic Reactions
A normal local reaction may include mild redness, swelling, warmth, itching, or soreness around the bite. These changes often remain near the bite and gradually fade.
An allergic reaction can cause widespread hives, facial or throat swelling, wheezing, dizziness, or trouble breathing. Those symptoms may indicate anaphylaxis, so call 911 immediately.
Avoid squeezing the tick or applying petroleum jelly, heat, or chemicals before removal.
Possible Signs of Tick-Borne Illness
During the days or weeks after a bite, watch for:
- Fever or chills
- Headache, fatigue, muscle aches, or muscle pain
- Joint pain
- Nausea or vomiting
- Swollen lymph nodes
- A new rash
Lyme disease may cause erythema migrans, an expanding rash that can resemble a bull’s-eye rash, though it does not always have that pattern. Rocky Mountain spotted fever, ehrlichiosis, anaplasmosis, tularemia, and other infections can also cause rashes.
When to Seek Urgent Medical Care
Seek urgent care for trouble breathing, facial swelling, fainting, severe headache, confusion, chest symptoms, repeated vomiting, or rapidly worsening illness. Get immediate evaluation for new weakness, difficulty walking, swallowing problems, or paralysis, which may signal tick paralysis or another neurologic emergency.
Contact a clinician promptly if fever, chills, rash, marked fatigue, muscle aches, joint pain, or swollen lymph nodes develop after a tick bite or outdoor exposure. Do not wait for a rash, and do not assume the absence of a rash rules out illness.
Diseases Ticks Can Spread in the United States
The United States has many tick species, and the illnesses they carry vary by region. Your risk can involve the deer tick, lone star tick, American dog tick, brown dog tick, or Rocky Mountain wood tick, among others.
Lyme Disease and Related Bacterial Infections
Lyme disease comes from Borrelia bacteria and is commonly associated with blacklegged ticks, often called deer ticks. Early symptoms can include erythema migrans, fever, headache, fatigue, and aches.
Later illness may involve joint pain, nerve problems, or heart complications. Other bacterial diseases include ehrlichiosis, anaplasmosis, tularemia, and relapsing fever, including tick-borne relapsing fever.
Tularemia comes from Francisella tularensis. Southern tick-associated rash illness, or STARI, can follow a lone star tick bite and may resemble Lyme disease, though its cause and treatment differ.
Rocky Mountain Spotted Fever and Other Serious Illnesses
Rocky Mountain spotted fever, commonly abbreviated RMSF, can become severe quickly. Fever, headache, muscle pain, nausea, and rash are possible symptoms, and early medical evaluation is important.
The American dog tick, brown dog tick, and Rocky Mountain wood tick can be associated with different regional infections. Your clinician may use your location, tick exposure, symptoms, and laboratory testing when deciding whether to prescribe antibiotics.
Viral, Parasitic, and Allergy-Related Conditions
Ticks can transmit viral diseases such as Colorado tick fever, Heartland virus, and Powassan virus. Some infections can affect the nervous system, causing severe headache, confusion, seizures, or weakness.
Babesiosis is a parasitic infection that can cause fever, fatigue, chills, and anemia. In addition, a bite from a lone star tick may trigger alpha-gal syndrome, an allergy to a carbohydrate found in many mammalian products.
Delayed hives, stomach symptoms, or breathing difficulty after eating beef, pork, lamb, or consuming mammal-derived products needs medical evaluation.
What to Do After Finding a Tick
Act calmly and remove the tick as soon as possible. The CDC’s tick-removal instructions recommend using fine-tipped tweezers, pulling steadily, and cleaning the bite area afterward.
Safe Tick Removal and Bite-Site Care
- Use clean, fine-tipped tweezers to grasp the tick as close to your skin as possible.
- Pull upward with slow, steady pressure. Avoid twisting or jerking.
- If mouthparts remain in the skin and cannot be removed easily, leave them alone and let the skin heal.
- Clean your hands and the bite site with soap and water or an alcohol-based cleanser.
- Dispose of the tick in alcohol, a sealed container, or a securely closed bag. Do not crush it with bare fingers.
Do not burn the tick, smother it with oil, or cover it with chemicals. Take a clear photograph if you want help identifying it, and note the date and location of the bite.
Monitoring Symptoms and Discussing Care With a Clinician
Record when you found the tick, where you acquired it, how long it may have been attached, and whether it looked engorged. Monitor the bite and your health for several weeks.
Call a clinician if you develop fever, chills, headache, fatigue, rash, muscle pain, joint pain, nausea, vomiting, or swollen lymph nodes. Depending on your exposure and local disease patterns, a clinician may recommend observation, testing, or antibiotics.
Do not self-treat with leftover medication.
Reducing Future Exposure
When you spend time in wooded or brushy areas, wear long sleeves and tuck your pants into your socks. Stay on cleared trails.
Apply an EPA-registered tick repellent containing DEET and follow the product label. Treat your clothing and gear with permethrin products made for that purpose. Never apply permethrin directly to your skin.
After you come indoors, check your body, clothing, children, and pets. Shower soon after outdoor activity.
Wash worn clothing appropriately and check your gear to help remove ticks before they attach. Regularly inspect common hiding places, including your scalp, behind your ears, underarms, waist, groin, and behind your knees.
