Very limited research has examined the direct effects of tick bites on blood sugar levels in humans.

Ticks may carry infectious bacteria, viruses, and parasites that could be transmitted to humans when they bite. The most common tick-borne infection is Lyme disease, which is typically caused by the bacterium Borrelia burgdorferi.

Some people with diabetes say that Lyme disease has led to more frequent blood sugar fluctuations, possibly due to the infection’s effect on insulin resistance.

But no research has examined the effect of Lyme disease, specifically on insulin resistance and blood sugar levels in humans.

The Centers for Disease Control and Prevention (CDC) notes that ticks may spread many different diseases in the United States. Some of these include:

Limited research has examined the effects of specific tick-borne illnesses and infections on blood sugar levels.

However, Diabetes UK notes that infections, in general, may cause high blood sugar (hyperglycemia) in people with diabetes due to insulin resistance.

As such, tick bites may theoretically affect your blood sugar levels indirectly if you contract an infection and have diabetes or insulin resistance.

But more research is needed to examine the effects of tick-borne illnesses on blood sugar levels.

A 2016 study in mice looked at how high blood sugar (hyperglycemia) affected the immune system’s protective defenses against Lyme disease.

When you’re exposed to an infection, your immune system releases a type of white blood cell called neutrophils to help protect your body. Neutrophils play a key role in responding to Borrelia burgdorferi, the main bacteria associated with Lyme disease.

The researchers found that hyperglycemia caused neutropenia in mice, a condition involving low neutrophils in the blood. This, in turn, reduced the immune system’s ability to detect, kill, and clear away Borrelia burgdorferi.

Neutropenia caused by high blood sugar may result in more severe Lyme disease symptoms and disease progression.

Despite these findings, however, it’s important to remember that this is an animal study. Very few human studies have examined the effects of hyperglycemia on Lyme disease symptoms and progression.

If you experience a tick bite, correctly remove it as soon as possible.

Speak with a healthcare professional if you experience Lyme disease symptoms like a bulls-eye rash, fatigue, and muscle aches. Early treatment could help treat the infection and prevent complications.