Lyme disease, also known as Lyme borreliosis, is an infectious disease caused by a bacterium named Borrelia burgdorferi sensu lato found in and spread by ticks.

The tick becomes infected after feeding on infected deer or mice. The infection is spread to humans by a bite from an infected black-legged or deer tick.

Symptom of Lyme Disease
Just like hypertension, Lyme disease can affect multiple body systems and produce a broad range of symptoms.

It is important to note that not all patients with Lyme disease have all symptoms, and many of the symptoms are not specific to Lyme disease, but can occur with other diseases, as well.

The most common sign of lyme disease in the early stage is an expanding area of redness on the skin, known as erythema migrans, that appears at the site the tick bite about a week or two after the bite.

Lyme disease causes a rash, often in a bull's-eye pattern, and flu-like symptoms. Joint pain and weakness in the limbs can occur as well.

In the second stage usually referred to as the early disseminated stage when the bacteria has started spreading throughout the body, symptoms such as chills, fever, enlarged lymph nodes, sore throat, vision changes, fatigue, muscle aches, headaches, will occur.

If still left untreated, the disease will get to the third stage referred to as late disseminated stage and this stage is characterized by severe headaches, arthritis of one or more large joints, disturbances in heart rhythm, brain disorders (encephalopathy) involving memory, mood, and sleep, short-term memory loss, difficulty concentrating, mental fogginess, problems following conversations, numbness in the arms, legs, hands, or feet.

The rash is typically neither itchy nor painful.  If untreated, symptoms may include loss of the ability to move one or both sides of the face, joint pains, severe headaches with neck stiffness, or heart palpitations, among others. Months to years later, repeated episodes of joint pain and swelling may occur.

Occasionally, people develop shooting pains or tingling in their arms and legs. Despite appropriate treatment, about 10 to 20% of people develop joint pains, memory problems, and tiredness for at least six months.

Causes Of Lyme Disease
Lyme disease is caused by spirochetes, spiral bacteria from the genus Borrelia. Spirochetes are surrounded by peptidoglycan and flagella, along with an outer membrane similar to other Gram-negative bacteria. Because of their double-membrane envelope, Borrelia bacteria are often mistakenly described as Gram negative despite the considerable differences in their envelope components from Gram-negative bacteria.

The Lyme-related Borrelia species are collectively known as Borrelia burgdorferi sensu lato, and show a great deal of genetic diversity.