Diseases & Conditions Archive

What Is It?

Squamous cells are small, flat skin cells in the outer layer of skin. When these cells become cancerous, they typically develop into flat or raised, rounded skin tumors. Sometimes the skin around the tumors gets red and swollen.

Most cases of squamous cell carcinoma occur in people who have spent lots of time in the sun—especially those with fair skin and blue eyes. Some cases develop on skin that has been injured or exposed to cancer-causing agents. This type of squamous cell cancer can develop on:

What Is It?

A drooping eyelid is also called ptosis or blepharoptosis. In this condition, the border of the upper eyelid falls to a lower position than normal. In severe cases, the drooping eyelid can cover all or part of the pupil and interfere with vision.

Ptosis can affect one or both eyes. It may be present at birth (congenital ptosis), or it may develop gradually over decades. Sometimes ptosis is an isolated problem that changes a person's appearance without affecting vision or health. In other cases, however, it can be a warning sign that a more serious condition is affecting the muscles, nerves, brain or eye socket. Ptosis that develops over a period of days or hours is more likely to signify a serious medical problem.

What Is It?

Hearing loss is a decrease in the ability to perceive sounds. It can be partial or total, sudden or gradual, temporary or permanent. It can affect one ear or both. In general, the risk of hearing loss increases with age.

Sound enters the ear and strikes the eardrum. This causes the eardrum to vibrate. The eardrum's vibrations are amplified through the middle ear by three tiny bones. Inside the ear, the vibrations are transformed into nerve impulses. These nerve impulses travel to the brain, where they are interpreted as sounds.

What Is It?

Hepatitis is inflammation of the liver. There are several types of hepatitis. The disease has several causes.

One cause of hepatitis is infection. Most cases of infectious hepatitis in the United States are caused by hepatitis A, B or C virus.

What Is It?

Multiple sclerosis (MS) is a neurological illness that affects the brain and spinal cord. Symptoms of the disease be intermittent (they come and go). Or MS can be progressive. This means it worsens over time. 

Nerve cells called neurons send out long "fingers" called axons.  The axons from one neuron send signals to another neuron that may be a long ways away.  A substance called myelin normally is wrapped around the axons. Myelin helps the axon transmit signals from one neuron to another.  

What Is It?

A tic is a sudden, rapid, repetitive movement (motor tic) or vocalization (vocal tic).

There are two main types of tics:

• Simple tics involve one muscle group
  • Simple motor tics include head shaking, eye blinking, sniffing, neck jerking, shoulder shrugging and grimacing. These are more common.
  • Simple vocal tics include coughing, throat clearing and barking.
• Complex tics involve more than one muscle group
  • Complex motor tics include self-hitting or self-biting, jumping and hopping, and twirling while walking.
  • Complex vocal tics include repeating words out of context, echoing what someone else said and speaking obscenities.

Tics sometimes change over time from one simple type of tic to another or from a simple to a complex tic. Some tics are slow and sustained rather than brief and rapid. Some involve the lower body.