As the weather gets warmer, the bugs are coming out to play — and carrying nasty diseases with them. The number of illnesses being transmitted by mosquitoes, ticks and flea bites have tripled in the United States, according to a new report from the Centers for Disease Control and Prevention. In all, 642,602 cases of disease have been reported from 2004 to 2016, more than 60 percent of which circle back to ticks. In fact, the number of tick-borne disease cases has more than doubled in the last 13 years. So why the uptick? Ticks and the diseases they spread are increasing and making their way into new regions. Plus, people are traveling more than ever, boosting the odds of bringing an infection home from another country, where rarer diseases may be robust. The CDC identifies tick-borne illnesses as a public health threat and admits the problem is widespread and difficult to control. While these diseases occur across the U.S., the Northeast, upper Midwest and southern parts of the country seem to be particularly vulnerable. Which diseases should you look out for? Six of them are on the rise, according to the CDC. Here’s what you should know about each one and how protect yourself from a bite this summer. Lyme DiseaseWhat it is: Lyme disease is an infection caused by bacteria that’s transmitted through the bite of an infected black-legged tick. Symptoms: If left untreated, Lyme disease can cause a vast variety of flu-like symptoms, depending on how long you’ve been infected. This includes fever, chills, headache, fatigue, joint aches and swollen lymph nodes. Perhaps the most recognizable sign of Lyme is a rash that takes the shape of a bulls-eye. Symptoms become more severe the longer you go without treatment, leading to shooting pains in your hands and feet, nerve pain, irregular heartbeat, facial palsy or even inflammation of your brain and spinal cord. How common it is: Lyme disease accounted for 82 percent of all tick-borne diseases reported from 2004 to 2016, the CDC report found, rising from 19,804 cases in 2004 to 36,429 cases in 2016. A total of 402,502 cases have been reported in that span of time.However, the CDC estimates that roughly 300,000 Americans are infected with Lyme each year, which is eight to 10 times higher than the number of cases actually reported. While Lyme typically occurs in the Northeast and upper Midwest, the disease has been making its way to other parts of the country.Anaplasmosis and EhrlichiosisWhat it is: Both anaplasmosis and ehrlichiosis are infections caused by bacteria that is transmitted through the bite of infected ticks. Anaplasmosis is commonly spread by black-legged ticks, while ehrlichiosis is spread by the Lone Star tick.Symptoms: Both diseases exhibit similar symptoms, which include fever, headache, muscle pain, malaise, chills, stomach pain, nausea, cough and confusion. Sometimes a rash may occur, but it is more common in ehrlichiosis than anaplasmosis. A rash is still considered rare in both illnesses.How common it is: Anaplasmosis and ehrlichiosis are currently the second-most common tick-borne diseases affecting Americans, growing from 875 cases in 2004 to 5,750 in 2016. Nearly 40,000 cases total have been reported during that time frame, the CDC says.Rocky Mountain Spotted FeverWhat it is: Spotted fever rickettsiosis, also known as Rocky Mountain spotted fever, is a bacterial disease spread through several species of infected ticks.Symptoms: Early signs of RMSF include fever, headache, nausea and vomiting, stomach pain, muscle pain and lack of appetite. The most common sign is a rash that usually develops two to four days after infection, the CDC says, which can make RMSF difficult to detect in its earliest stages. The appearance of the rash also varies; some can be red and splotchy, while others look like pinpoint dots. RMSF rapidly progresses and can become life-threatening if not treated properly. Because the disease is hard to detect in its earliest stages, the CDC recommends seeing your doctor immediately if you feel sick after being bitten by a tick or hanging out in wooded or high-brush areas. How common it is: RMSF grew from 1,713 cases in 2004 to 4,269 cases in 2016, with a total of more than 37,000 reported cases during that time frame. RMSF occurs throughout the U.S. but has most commonly been reported in North Carolina, Tennessee, Missouri, Arkansas and Oklahoma, the CDC says. Babesiosis What it is: Babesiosis is caused by microscopic parasites that infect your red blood cells. It’s most commonly transmitted through black-legged or deer ticks. Symptoms: Babesiosis typically doesn’t present many symptoms. In fact, many infected people may feel fine for a while. If symptoms do pop up, they can start within a week after infection but usually develop weeks, months or even longer after you’ve been infected. Common signs include fever, chills, sweats, body aches, nausea or fatigue. Babesiosis can cause hemolytic anemia, a condition in which your red blood cells are destroyed. It can also be life-threatening in people who are older or have a weak immune system and other serious health conditions, like cancer or kidney disease.How common it is: In 2004, there were no reported cases of babesiosis. That number grew to 1,910 in 2016. While it has steadily trended upwards, reports of babesiosis slightly decreased between 2015 and 2016. Most cases occur in the Northeast and upper Midwest of the U.S.Tularemia What it is: Tularemia is caused by a highly infectious bacteria that is transmitted by dog, wood, or Lone Star ticks. Symptoms: There are several types of tularemia, but two of the most common forms associated with tick bites are ulceroglandular and glandular, according to the CDC. In ulceroglandular tularemia, a skin ulcer — a raw, red or painful sore — will appear where the bacteria entered your body. This leads to swelling in certain glands, typically in your armpit or groin. Glandular tularemia is similar but does not produce an ulcer. Both forms also cause fever, which can be as high as 104 degrees. How common it is: Tularemia does not occur as frequently as other tick-borne diseases, but it has been on the rise. Only 134 cases were reported in 2004, which grew to 230 in 2016. Tularemia can occur across the U.S., but tends to be more common in central parts of the country, the CDC report states. Powassan VirusWhat it is: Powassan virus is transmitted by the bite of an infected tick and cannot be spread directly from person to person. Symptoms: People get sick from one week to a month after infection, but many do not develop any symptoms. Common signs include fever, headache, vomiting, weakness, confusion, loss of coordination, difficulty speaking and seizures. POW virus is a serious disease and can cause inflammation of the brain or meningitis. There is currently no specific medicine designed to treat POW virus disease.How common it is: Powassan virus is rare in the U.S. Only one case was reported each year between 2004 and 2006. However, that number jumped to 22 cases in 2016, the highest it has been in 13 years. Most cases have popped up in the Northeast or Great Lakes regions of the U.S.How to Protect Yourself From Tick BitesFear of ticks shouldn't stop you from enjoying your summer. The CDC says there are few things you can do protect yourself from ticks (as well as mosquitoes and fleas) once outdoor season goes full swing:Use an insect repellent that contains 20 percent or more DEET, picaridin or IR3535 on any exposed skin. (OFF! Deep Woods Insect Repellent contains 25 percent DEET.)Cover up! Opt for long-sleeved shirts and long pants if you will be in wooded or high brush areas.Treat your clothing, gear and tents with a product that contains at least 0.5 percent permethrin.Always do a full-body check after you’ve spent time outdoors, and shower as soon as you possibly can.Tumble dry your dry clothes on high heat for 10 minutes to kill any ticks you bring inside with you. (If your clothes require washing, use hot water and tumble dry on high for an hour.)Check for and remove ticks from your pets daily.