Do you work outdoors? Do you hike or camp frequently? Do you share your home with a pet that has recently had a tick problem? If so, be on the watch for ticks.

These parasitic arachnids (they are cousins of the spider) are often difficult to detect with the naked eye, but they can wreak havoc on your health. And, unless you’re allergic, you won’t even feel the pinch or itch of a tick’s bite; many ticks actually manufacture and secrete their own pain-killing chemicals so their hosts remain unaware of their presence.

Unfortunately, the longer a tick has been feeding, and the more engorged with blood it has become, the more you may be at risk of contracting a serious infection. And some adult ticks can stay attached to your body for upwards of a week.

Your best defense against these blood-sucking bugs and the diseases they spread is close inspection. Properly identifying engorged ticks can help reduce the risk of complications from tick-borne diseases. Look for these signs and symptoms that you may be carrying one of these freeloading pests.

"Beware the Blob

Look for any unusual raised areas on exposed skin as you inspect for ticks. As these arachnids feed, they actually expand in order to accommodate the amount of blood they ingest. And, because ticks can feed on a single host for as many as seven days, both young and adult ticks can swell to several times their original size. In fact, fully engorged ticks can balloon to up one-quarter to two-thirds inch in diameter. Partially engorged ticks typically measure about one-eighth inch in diameter. 

White Ticks

In addition to being very small, the majority of ticks are black or dark brown in color. But because they are full of blood, engorged ticks will often have a silver, green-grey or even white appearance. In fact, "white tick" is just a colloquial name for an engorged tick; they are one and the same.

Check the Coat of Arms

All hard-bodied ticks—a category that includes such common pests as the dog tick, the black-legged (or deer) tick and the Lone Star tick—sport a hard plate above their heads. This plate (known as a scutum) features a color and pattern unique to each species of tick and can help you to differentiate an engorged tick from another skin condition such as a blister, boil or wart. Look for dark, striped or spotted patches near the base of “the blob” should you suspect you’ve discovered an engorged tick in your inspections.

Consult Your Calendar

Ticks are most active and dangerous beginning in late spring and through the summer months. July is usually the peak of tick season, as young ticks, known as nymphs, disperse in search of food. 

Toe to Head

Ticks can attach anywhere, but they are most likely to latch onto your feet, ankles, shins, armpits and ears. Ticks like to hang out in piles of dead leaves and in tall grass and are experts at waiting patiently for a host to pass by. Begin your inspection by starting low (feet, ankles, shins) and moving up (armpits and ears). Be sure to check nooks and crannies (behind the knees, under arms, inside the navel, etc.), and don’t be shy about asking for help looking in places you can’t easily see.

Do Not Disturb

Do not scratch, squeeze, or pull at what you suspect may be an engorged tick to see if it responds to such prodding. An anchored tick is a living tick, and its specialized jaws are working away just beneath the surface of your skin. Disturbing an engorged tick can actually force the parasite’s digestive fluids back into your bloodstream, and it's these fluids that can contain the bacteria (Borrelia burgdorferi) that cause Lyme disease. The Centers for Disease Control and Prevention advises removing ticks, and engorged ticks, in particular, with tweezers and disposing of them with caution (e.g., placed in a secure container and doused with isopropyl alcohol). If you have removed an engorged tick and you develop a reddish rash around the site of a tick bite, suffer arthritis-like pain in one or more joints or experience flu-like symptoms, be sure to promptly check with your physician.