Lyme disease explained: Symptoms, ticks, treatments and the states where cases occur

Show Caption Hide Caption CDC: If you spot a tick, grab the tweezers Higher temperatures in January mean an increase in ticks come summer. Angeli Kakade (@angelikakade) has the story.

May begins the three-month span during which more people will get tick bites than any other in the United States, according to the Centers for Disease Control. And that means more risk of Lyme disease, a tick-borne infection that the agency warns is on the rise.

While some 30,000 cases of Lyme disease get reported annually, the CDC suggests the actual number of diagnosed cases may be ten times that — about 300,000. If not treated, Lyme disease can produce severe arthritis or cause neurological or cardiac problems.

Here are the states where Lyme disease is most confirmed, common symptoms and treatments and key tips to avoiding it.

Almost all Lyme disease cases unfold in these states

Ninety-five percent of all confirmed Lyme disease cases in 2015 stemmed from just 14 states, according to the CDC: Connecticut, Delaware, Maine, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Virginia and Wisconsin. And while reported cases stem largely from the Northeast and upper Midwest, a 2016 study in the Journal of Medical Entomology found ticks that carry Lyme disease present in nearly half of all U.S. counties.

How to avoid disease-carrying ticks

When walking in wooded or grassy areas, wear light-colored clothing to help spot ticks easily and tuck pants into socks and shirts into pants. While outside, walk in the center of trails and avoid areas with high grass. Frequently check for ticks on clothing and on skin. Bathe or shower within two hours of being outdoors in wooded or grassy areas, or as soon as possible.

At the end of each day, do a full-body tick check on yourself, children and pets. The CDC also recommends tumble drying clothes worn outside on high for 10 minutes to kill any ticks present. Check pets every day if they are allowed outdoors, as pets can bring ticks into the home.

How to remove a tick — and where to check

In most cases, a tick must attach itself to a person for 36 to 48 hours before the Lyme bacteria can be transferred, per the CDC. Ticks often attach themselves to warm areas such as the knees, behind the ears, groin, armpits and hairline.

If you find a tick, use fine-tipped tweezers to grasp it by the head as close to the skin as possible. Gently pull the tick upward, making sure not to twist or squeeze it. If you're uncomfortable removing the tick yourself, seek medical attention.

Symptoms that could mean Lyme disease

Early stages of Lyme disease are usually marked with fatigue, chills, fever, headache, muscle and joint pain, and swollen lymph nodes. These flu-like symptoms can seem like other diseases, meaning patients and doctors may not test for it. In 60 percent to 80 percent of cases, however, a "bull's-eye" or red rash appears on the skin. This rash may be on the bite site or other locations on the body and will expand over time.

Lyme disease is often treated with antibiotics, either oral or intravenous, for multiple weeks.

So what is Lyme disease, exactly?

Lyme disease is caused by an infection with bacteria called Borrelia Burgdorferi, which is carried in the gut of different types of ticks. The germ is transferred to the blood stream about a day or two after an infected tick attaches and starts to feed. The diagnoses of Lyme is often straightforward, but sometimes requires a blood test that's not always reliable.

More: Alec Baldwin, Avril Lavigne and other celebrities who've battled Lyme disease

More: Swatting at mosquitoes, even if you miss, trains them to stay away