myelopathies

Your spinal cord is a bundle of nerves that runs down the middle of your back. It carries signals back and forth between your body and your brain. It is protected by your vertebrae, which are the bone disks that make up your spine. If you have an accident that damages the vertebrae or other parts of the spine, this can also injure the spinal cord. Other spinal cord problems include:

• Tumors
• Infections such as meningitis and polio
• Inflammatory diseases
• Autoimmune diseases
• Degenerative diseases such as amyotrophic lateral sclerosis and spinal muscular atrophy

Symptoms vary but might include pain, numbness, loss of sensation and muscle weakness. These symptoms can occur around the spinal cord, and also in other areas such as your arms and legs. Treatments often include medicines and surgery.

Any part of your neck - muscles, bones, joints, tendons, ligaments, or nerves - can cause neck problems. Neck pain is very common. Pain may also come from your shoulder, jaw, head, or upper arms.

Muscle strain or tension often causes neck pain. The problem is usually overuse, such as from sitting at a computer for too long. Sometimes you can strain your neck muscles from sleeping in an awkward position or overdoing it during exercise. Falls or accidents, including car accidents, are another common cause of neck pain. Whiplash, a soft tissue injury to the neck, is also called neck sprain or strain.

Treatment depends on the cause, but may include applying ice, taking pain relievers, getting physical therapy or wearing a cervical collar. You rarely need surgery.

Your spine, or backbone, protects your spinal cord and allows you to stand and bend. Spinal stenosis causes narrowing in your spine. The narrowing puts pressure on your nerves and spinal cord and can cause pain.

Spinal stenosis occurs mostly in people older than 50. Younger people with a spine injury or a narrow spinal canal are also at risk. Diseases such as arthritis and scoliosis can cause spinal stenosis, too. Symptoms might appear gradually or not at all. They include:

• Pain in your neck or back
• Numbness, weakness, cramping, or pain in your arms or legs
• Pain going down the leg
• Foot problems

Doctors diagnose spinal stenosis with a physical exam and imaging tests. Treatments include medications, physical therapy, braces, and surgery.

NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases

Viruses are very tiny germs. They are made of genetic material (either DNA or RNA) inside of a protein coating. There are a huge number of viruses on earth. Only a small number of them can infect humans. Those viruses can infect our cells, which may cause disease. Some of the diseases that viruses can cause include the common cold, the flu, COVID-19, and HIV.

Viruses can be spread in different ways:

• Through droplets and particles that are breathed out by someone who has the infection. You might breathe in the droplets or particles, or they could land on your mouth, nose, or eyes.
• By touching surfaces or objects that have the virus on them and then touching your mouth, nose, or eyes.
• From the pregnant parent to the baby during pregnancy.
• Through contaminated food or water.
• By being bitten by an infected insect or animal.
• Through sexual contact (usually vaginal, anal and oral sex) with someone who has the infection.

Viruses are like hijackers. They invade living, normal cells. They then use those cells to multiply (make copies of themselves). This process is also called replication. The process can kill, damage, or change the infected cells. Sometimes this can make you sick. The symptoms can range from mild to very severe. Other times, your immune system may be able to fight it off and you may not have any symptoms.

Each different virus usually only infects one type of cell in your body. For example, hepatitis viruses affect the cells in the liver. HIV infects a certain type of immune system cell.

For most viral infections, treatments can only help with symptoms while you wait for your immune system to fight off the virus. There are antiviral medicines to treat some viral infections. Antibiotics do not work for viral infections.

Vaccines can help prevent you from getting many viral diseases. You may be able to prevent some viral infections by:

• Proper hand washing.
• Paying attention to food safety.
• Cleaning surfaces that may be infected with germs.
• Avoiding contact with wild animals.
• Preventing insect bites by using insect repellent when you go outdoors. If you travel to an area that has a high risk of diseases from insect bites, also wear long pants, shirts, and socks.
• Practicing safe sex (using a condom every time you have anal, vaginal, or oral sex).
• Avoiding close contact with people who are sick.

The brain, spinal cord, and nerves make up the nervous system. Together they control all the workings of the body. When something goes wrong with a part of your nervous system, you can have trouble moving, speaking, swallowing, breathing, or learning. You can also have problems with your memory, senses, or mood.

There are more than 600 neurologic diseases. Major types include:

• Diseases caused by faulty genes, such as Huntington's disease and muscular dystrophy
• Problems with the way the nervous system develops, such as spina bifida
• Degenerative diseases, where nerve cells are damaged or die, such as Parkinson's disease and Alzheimer's disease
• Diseases of the blood vessels that supply the brain, such as stroke
• Injuries to the spinal cord and brain
• Seizure disorders, such as epilepsy
• Cancer, such as brain tumors
• infections, such as meningitis