Caffeine is a bitter substance found in coffee, tea, soft drinks, chocolate, kola nuts, and certain medicines. It has many effects on the body’s metabolism, including stimulating the central nervous system. This can make you more alert and give you a boost of energy.
For most people, the amount of caffeine in two to four cups of coffee a day is not harmful. However, too much caffeine can cause problems. It can
- Make you jittery and shaky
- Make it hard to fall asleep or stay asleep
- Cause headaches or dizziness
- Make your heart beat faster or cause abnormal heart rhythms
- Cause dehydration
- Make you dependent on it so you need to take more of it. If you stop using caffeine, you could get withdrawal symptoms.
Some people are more sensitive to the effects of caffeine than others. They should limit their use of caffeine. So should pregnant and nursing women. Certain drugs and supplements may interact with caffeine. If you have questions about whether caffeine is safe for you, talk with your health care provider.
Sciatica is a symptom of a problem with the sciatic nerve, the largest nerve in the body. It controls muscles in the back of your knee and lower leg and provides feeling to the back of your thigh, part of your lower leg, and the sole of your foot. When you have sciatica, you have pain, weakness, numbness, or tingling. It can start in the lower back and extend down your leg to your calf, foot, or even your toes. It’s usually on only one side of your body.
Causes of sciatica include
- A ruptured intervertebral disk
- Narrowing of the spinal canal that puts pressure on the nerve, called spinal stenosis
- An injury such as a pelvic fracture.
In many cases no cause can be found.
Sometimes sciatica goes away on its own. Treatment, if needed, depends on the cause of the problem. It may include exercises, medicines, and 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.
Your backbone, or spine, is made up of 26 bone discs called vertebrae. The vertebrae protect your spinal cord and allow you to stand and bend. A number of problems can change the structure of the spine or damage the vertebrae and surrounding tissue. They include
- Conditions, such as ankylosing spondylitis and scoliosis
- Bone changes that come with age, such as spinal stenosis and herniated disks
Spinal diseases often cause pain when bone changes put pressure on the spinal cord or nerves. They can also limit movement. Treatments differ by disease, but sometimes they include back braces and surgery.
In the vertebrate spinal column, each vertebra is an irregular bone with a complex structure composed of bone and some hyaline cartilage, the proportions of which vary according to the segment of the backbone and the species of vertebrate.
The basic configuration of a vertebra varies; the large part is the body, and the central part is the centrum. The upper and lower surfaces of the vertebra body give attachment to the intervertebral discs. The posterior part of a vertebra forms a vertebral arch, in eleven parts, consisting of two pedicles, two laminae, and sevenprocesses. The laminae give attachment to the ligamenta flava (ligaments of the spine). There are vertebral notches formed from the shape of the pedicles, which form the intervertebral foramina when the vertebrae articulate. These foramina are the entry and exit conducts for the spinal nerves. The body of the vertebra and the vertebral arch form the vertebral foramen, the larger, central opening that accommodates the spinal canal, which encloses and protects the spinal cord.
Vertebrae articulate with each other to give strength and flexibility to the spinal column, and the shape at their back and front aspects determines the range of movement. Structurally, vertebrae are essentially alike across the vertebrate species, with the greatest difference seen between an aquatic animal and other vertebrate animals. As such, vertebrates take their name from the vertebrae that compose the vertebral column.