Lyme Disease: Diagnosis, Symptoms, and Treatment

Lyme disease is the most common tick-borne illness in the US. It’s caused by a bacterium transmitted through the bite of an infected deer tick. Most cases are treatable. The tricky part is that symptoms can vary a lot, and many people don’t realize they’ve been bitten by ticks.

We analyzed hundreds of recommendations from Sesame’s doctors, practitioners, and physicians to see how Lyme disease actually presents and gets treated. Here’s what we found.

Symptoms of Lyme disease

Symptoms of Lyme disease can be incredibly deceptive. They evolve over time and vary wildly from person to person. When monitoring yourself or others after spending time outdoors, look out for these specific warning signs:

• On the skin: The most definitive sign is erythema migrans, the famous "bull’s-eye" rash that expands outward from the bite site. It typically appears within 3 to 30 days (averaging about a week), is usually non-itchy and painless, and can range from the size of a coin to several inches across. Note that 10% to 20% of people develop multiple rashes, while others never get one at all.
• Flu-like symptoms: Profound, unexplained fatigue is the most common complaint among patients. This is frequently accompanied by a low-grade fever (99°F to 101.4°F), chills, night sweats, headaches, and swollen lymph nodes in the neck or armpits.
• In the joints and muscles: Early on, you may experience general muscle aches and a stiff neck. If the infection advances, it can cause acute joint pain and visible swelling—known as Lyme arthritis—typically targeting large joints like the knees and ankles.
• Neurological changes: In later stages, patients may experience shooting or burning pains down the arms, hand numbness or tingling, and severe dizziness when standing up. It can also cause short-term memory lapses and difficulty concentrating, commonly referred to as "brain fog."
• Signs in children: While kids experience the same physical symptoms as adults, they are uniquely prone to psychological shifts. Sudden emotional outbursts, cognitive difficulties in school, and noticeable shifts in personality are often the clearest indicators for parents.

Common bite locations on the body

Ticks tend to settle in warm, hidden areas of the body. This means they rarely settle in obvious places. When returning from a wooded area, a golf course, or even doing basic yard work, you should thoroughly check yourself from head to toe.

To ensure you don't miss a hidden danger, pay close attention to both the obvious areas and the hidden zones during your check:

• Highly visible zones: These are the straightforward areas like your ankles, shins, knees, thighs, arms, chest, and your upper and lower back.
• Hidden danger zones: These are the spots people regularly overlook, including the groin and scrotal area, the armpits, inside the belly button (navel), behind the ears, and deep within the scalp or at the base of the head. It can be useful to have someone else help you look at these hard-to-find spots.
• The distance factor: Keep in mind that a symptom can manifest far away from the actual bite. For example, an undetected tick bite on your ankle can cause severe, swollen lymph nodes to develop in your groin.

When you should seek emergency care

For most people, a standard case of Lyme disease is easily manageable. However, if the infection spreads to your nervous system or your heart, it can become more serious. Recognizing the warning signs of a more serious infection can make the difference between a routine recovery and a serious emergency.

If you or a loved one experience any of the following symptoms, skip the clinic and head directly to the nearest emergency room:

• Facial drooping or paralysis: This sudden weakness or loss of movement on one or both sides of your face is known as Bell's palsy. It can signal nervous system involvement.
• Severe neck stiffness: Strong stiffness in the neck, especially with a high fever, may suggest meningitis.
• Chest pain or heart palpitations: Fast or irregular heartbeat, palpitations, or shortness of breath can indicate Lyme carditis, an inflammation of the heart.
• Sudden confusion or coordination problems: Another warning sign is feeling very confused, extremely unsteady, or too dizzy to stand safely.

If neurological Lyme disease is suspected, the ER may perform a spinal tap to check if the central nervous system is involved.

How Lyme disease is diagnosed

You cannot rely on a quick blood test right after a tick bite. Testing too early is the most common reason infections are missed, leading to false negatives that delay necessary treatment. This is because standard lab tests look for the antibodies your immune system creates to fight the bacteria, not the bacteria themselves.

Because your body needs time to build up that defense, healthcare providers look at your overall situation rather than relying purely on early lab work. They will evaluate your health using three main factors:

• The waiting period: It typically takes 6 to 8 weeks for a blood test to show a reliable positive result. Testing during the first few days of a bite is rarely helpful.
• A clinical diagnosis: In the early stages, a provider will diagnose you based on your actual situation rather than waiting for a lab. They will look closely at your symptoms, your history of tick exposure, and whether you live in or have visited a high-risk area.
• Ruling out other conditions: Fatigue, joint pain, and brain fog are common to many illnesses. Healthcare providers will systematically rule out identical look-alikes. That way, they can make sure your symptoms aren’t actually caused by conditions like fibromyalgia, thyroid issues (Hashimoto’s), Crohn’s disease, or standard joint stiffness.

How Lyme disease is treated

Once a doctor confirms a diagnosis, the primary weapon against the infection is a course of oral antibiotics. However, treatment is rarely a one-size-fits-all prescription.

Your age, allergies, and the specific stage of the infection will all dictate what your provider prescribes and how long you will need to take the medication:

• The 72-hour preventative window: If you catch and remove a deer tick quickly, a single dose of doxycycline can stop Lyme disease before it even starts. This option is recommended if the tick was attached for 36 hours or more. At that point, it often looks swollen or engorged. You will then need to take the dose within 72 hours of removing it.
• Standard early-stage timeline: For a standard infection caught within the first few weeks, a simple 10- to 14-day course of oral antibiotics is typically all it takes to fully clear the bacteria.
• Advanced joint-stage timeline: If the infection has progressed to Lyme arthritis—causing noticeable swelling in the knees or ankles—the protocol changes. This advanced stage generally requires a strict 28- to 30-day course of oral antibiotics.
• Antibiotic variations: While doxycycline is the standard treatment for most adults and children, it is avoided during pregnancy because it can interfere with the development of a baby. Pregnant women are safely prescribed highly effective alternatives like amoxicillin or cefuroxime instead.

Managing side effects and follow-up care

The prescription antibiotics used to treat Lyme disease are exceptionally strong. That’s why they can cause their own side effects if you aren’t careful. Recovery is about more than just swallowing a pill. You need to protect your digestive system and your skin. It is also recommended to plan a follow-up consultation with your healthcare provider. That way you can ensure you are fully recovered.

Support your recovery by following these standard guidelines:

• Protect your stomach: Long courses of antibiotics can disrupt your digestive system and cause severe stomach upset. Doctors recommend taking your medicine with food and eating yogurt or taking probiotics daily to keep your gut healthy.
• Prevent severe sunburn: Doxycycline makes your skin highly sensitive to the sun. You can get a severe, blistering sunburn even from brief exposure, so wearing SPF 50 sunscreen every day during treatment is a must.
• Avoid throat irritation: If a doxycycline pill dissolves in your throat before reaching your stomach, it can cause painful irritation or ulcers. Always take your pill with a full glass of water and stay upright for at least 30 minutes afterward. Do not take it right before lying down.
• Handle pain and swelling: Common over-the-counter pain relievers like ibuprofen or acetaminophen work well for fevers and muscle aches. For constant, severe joint swelling in the knees or ankles, a doctor may prescribe a specific anti-inflammatory medicine like meloxicam.
• Follow a recovery schedule: Expect a structured follow-up plan. Providers usually want an initial check-in 3 to 5 days after a bite to monitor for new symptoms, a rash check within 1 to 7 days, a treatment evaluation at 2 to 4 weeks, and a blood test at 6 to 8 weeks if mild symptoms linger.

Who gets Lyme disease? Regions and seasons

The Centers for Disease Control and Prevention (CDC) tracks tick bites closely. They show clear patterns for where and when people get infected. Ticks need specific weather and environments to survive. This means your location and your outdoor activities heavily influence your overall risk.

Your chances of encountering an infected tick go up significantly if you are in these areas or environments:

• High-risk states: The vast majority of Lyme disease cases in the US happen in the Northeast and Mid-Atlantic states, the upper Midwest (including Ohio and Missouri), North Carolina, and Northern California.
• Summer months: Tick-related medical visits peak during June, July, and August. Spending time outdoors during the Fourth of July holiday weekend marks the highest time of year for tick bite consultations.
• High-risk environments: Most people cross paths with ticks in wooded areas, hiking trails, campgrounds, golf courses, and even during regular yard work close to bushes or areas with large deer populations.

Get same-day evaluation and treatment with Sesame

If you’ve found a tick, noticed an unusual rash, or have symptoms you’re not sure about, getting evaluated early can make a difference in how Lyme disease progresses.

Sesame’s licensed doctors, nurse practitioners, and physician assistants can assess your symptoms in a same-day virtual visit. During your call, your provider will review your exposure history, evaluate your symptoms, and, if needed, prescribe medications for same-day pickup at your local pharmacy.

Frequently asked questions

Can I get Lyme disease more than once?

Yes. A prior infection does not grant you long-term immunity. If another infected tick bites you in the future, you can contract Lyme disease again. On top of that, those with severe cases sometimes report a temporary return of the fatigue or joint pain years later. This is especially frequent during periods of high stress or illness. It’s important to consult with a healthcare professional if this is your case.

What should I do if the tick bite site is red but doesn’t look like a bull’s-eye?

A small red spot that appears immediately after a bite may just be a mild allergic reaction to the tick’s saliva, much like a mosquito bite. You should still pay attention to whether it grows. If the redness expands over several days, or if you develop flu-like symptoms, you should contact a healthcare provider immediately.

Can I get a blood test the day after the tick bite?

Your body will need time to recognize the bacteria. Only then will it build up a measurable level of antibodies. Testing the day after a bite will always give you a negative result, even if the bacteria are present. That’s why healthcare providers rely on your symptoms and exposure history. With this, they can start treatment early rather than waiting weeks for a blood test.

Is Lyme disease contagious?

No, Lyme disease is not among the infectious diseases people can transmit to each other. The only way humans can contract Lyme disease is through an infected tick bite. Only if this tick injects the bacteria directly into the bloodstream can the disease enter your system. You also can’t catch Lyme disease from a pet. Dogs and cats can bring ticks into the house. However, the animal itself cannot transmit the bacteria to you.