| Medical Dictionary |
A Medical Dictionary of Medical Terminology
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Sickle cell disease (SCD) is a group of inherited red blood cell disorders. If you have SCD, there is a problem with your hemoglobin. Hemoglobin is a protein in red blood cells that carries oxygen throughout the body. With SCD, the hemoglobin forms into stiff rods within the red blood cells. This changes the shape of the red blood cells. The cells are supposed to be disc-shaped, but this changes them into a crescent, or sickle, shape.
The sickle-shaped cells are not flexible and cannot change shape easily. Many of them burst apart as they move through your blood vessels. The sickle cells usually only last 10 to 20 days, instead of the normal 90 to 120 days. Your body may have trouble making enough new cells to replace the ones that you lost. Because of this, you may not have enough red blood cells. This is a condition called anemia, and it can make you feel tired.
The sickle-shaped cells can also stick to vessel walls, causing a blockage that slows or stops the flow of blood. When this happens, oxygen can't reach nearby tissues. The lack of oxygen can cause attacks of sudden, severe pain, called pain crises. These attacks can occur without warning. If you get one, you might need to go to the hospital for treatment.
What causes sickle cell disease (SCD)?The cause of SCD is a defective gene, called a sickle cell gene. People with the disease are born with two sickle cell genes, one from each parent.
If you are born with one sickle cell gene, it's called sickle cell trait. People with sickle cell trait are generally healthy, but they can pass the defective gene on to their children.
Who is more likely to have sickle cell disease (SCD)?In the United States, most of the people with SCD are African Americans:
SCD also affects some people who come from Hispanic, southern European, Middle Eastern, or Asian Indian backgrounds.
What are the symptoms of sickle cell disease (SCD)?People with SCD start to have signs of the disease during the first year of life, usually around 5 or 6 months of age. Early symptoms of SCD may include:
The effects of SCD vary from person to person and can change over time. Most of the signs and symptoms of SCD are related to complications of the disease. They may include severe pain, anemia, organ damage, and infections.
How is sickle cell disease (SCD) diagnosed?A blood test can show if you have SCD or sickle cell trait. All states now test newborns as part of their screening programs, so treatment can begin early.
People who are thinking about having children can have the test to find out how likely it is that their children will have SCD.
Health care providers can also diagnose SCD before a baby is born. That test uses a sample of amniotic fluid (the liquid in the sac surrounding the baby) or tissue taken from the placenta (the organ that brings oxygen and nutrients to the baby).
What are the treatments for sickle cell disease (SCD)?Treatments for SCD include:
To stay as healthy as possible, make sure that you:
NIH: National Heart, Lung, and Blood Institute
While you are sleeping, you are unconscious, but your brain and body functions are still active. Sleep is a complex biological process that helps you process new information, stay healthy, and feel rested.
During sleep, your brain cycles through five stages: stage 1, 2, 3, 4, and rapid eye movement (REM) sleep. Different things happen during each stage. For example, you have a different pattern of brain waves during each one. Your breathing, heart, and temperature may be slower or faster in some stages. Certain phases of sleep help you :
You need all of the stages to get a healthy sleep.
How much sleep do I need?The amount of sleep you need depends on several factors, including your age, lifestyle, health, and whether you have been getting enough sleep recently. The general recommendations for sleep are:
During puberty, teenagers' biological clocks shift, and they are more likely to go to bed later than younger children and adults, and they tend to want to sleep later in the morning. This delayed sleep-wake rhythm conflicts with the early-morning start times of many high schools and helps explain why most teenagers do not get enough sleep.
Some people think that adults need less sleep as they age. But there is no evidence to show that older adults can get by with less sleep than people who are younger. As people age, however, they often get less sleep or they tend to spend less time in the deep, restful stage of sleep. Older adults are also more easily awakened.
And it's not just the number of hours of sleep you get that matters. The quality of the sleep you get is also important. People whose sleep is frequently interrupted or cut short might not get enough of certain stages of sleep.
If you are wondering whether you are getting enough sleep, including quality sleep, ask yourself:
If you answered yes to these three questions, you should work on improving your sleep.
What are the health effects of not getting enough sleep?Sleep is important for overall health. When you don't get enough sleep (sleep deprivation), it does more than just make you feel tired. It can affect your performance, including your ability to think clearly, react quickly, and form memories. This may cause you to make bad decisions and take more risks. People with sleep deprivation are more likely to get into accidents.
Sleep deprivation can also affect your mood, leading to:
It can also affect your physical health. Research shows that not getting enough sleep, or getting poor-quality sleep, increases your risk of:
Not getting enough sleep can also mean that you don't get enough of the hormones that help children grow and help adults and children build muscle mass, fight infections, and repair cells.
Sleep deprivation magnifies the effect of alcohol. A tired person who drinks too much alcohol will be more impaired than a well-rested person.
How can I get better sleep?You can take steps to improve your sleep habits. First, make sure that you allow yourself enough time to sleep. With enough sleep each night, you may find that you're happier and more productive during the day.
To improve your sleep habits, it also may help to:
If you are a shift worker, it can be even harder to get a good sleep. You may also want to:
Colorectal cancer is cancer that develops in the tissues of the colon or rectum. Your colon and rectum are part of your digestive system:
Cancer that begins in the colon is called colon cancer, and cancer that begins in the rectum is called rectal cancer. Cancer that affects either of these parts may also be called colorectal cancer.
What causes colorectal cancer?Colorectal cancer happens when there are changes in your genetic material (DNA). These changes are also called mutations or variants. Often, the genetic changes that lead to colorectal cancer happen during your lifetime and the exact cause is unknown. But certain genetic changes that raise your risk for colorectal cancer are inherited, meaning that you are born with them.
Besides genetics, other factors, including your lifestyle and the environment, can affect your risk of colorectal cancer.
Who is more likely to develop colorectal cancer?Anyone can get colorectal cancer, but certain factors make you more likely to develop it:
Colorectal cancer may not always cause symptoms, especially at first. If you do have symptoms, they could include:
Because colorectal cancer may not cause symptoms at first, it's important to have screening tests for colorectal cancer. Screening tests look for signs of a disease before you have any symptoms. They can help find cancer early, when it may be easier to treat.
Most experts recommend that start screenings at 45 and continue until at least age 75. People over 75 and those who are at high risk should talk to their providers about how often you need screening and what type of test they should get.
The types of tests include different stool tests and procedures such as colonoscopies and flexible sigmoidoscopy. Talk with your provider about how often you need screening and what type of test you should get.
How is colorectal cancer diagnosed?If you have symptoms that could be caused by colorectal cancer or if your screening test results are abnormal, you may need to have more tests to find out if you have cancer. Possible tests include:
Your treatment options usually depend on your age, your general health, how serious the cancer is, and which type of cancer you have.
For colon cancer, your treatment may include one or more of these options:
For rectal cancer, your treatment may include one or more of these options:
Avoiding the risk factors that you have control over may help prevent some cancers. That includes:
There are also other steps you can take to try to prevent colorectal cancer. They include:
Exercise and physical activity are good for just about everyone, including older adults. There are four main types and each type is different. Doing them all will give you more benefits.:
If you have not been active, you can start slowly and work up to your goal. How much exercise you need depends on your age and health. Check with your health care provider on what is right for you.
NIH: National Institute on Aging
Stress is how your brain and body respond to a challenge or demand. When you are stressed, your body releases certain hormones. Hormones are chemicals that travel in your bloodstream and control how different parts of your body work. The hormones that are released when you are stressed make you alert and ready to act. They can raise your blood pressure, heart rate, and blood glucose (blood sugar) levels. This response is sometimes called a "fight or flight" response.
Everyone gets stressed from time to time. There are different types of stress. It can be short-term or long-term. It can be caused by something that happens once or something that keeps happening.
Not all stress is bad. In fact, it can help you survive in a dangerous situation. For example, one kind of stress is the jolt you may feel when a car pulls out in front of you while you are driving. This jolt of hormones helps you quickly hit the brakes to avoid an accident. A little short-term stress can sometimes be helpful. For example, the stress of having a deadline for school or your job may push you to get your work done on time. Once you finish it, that stress goes away.
But stress that lasts a long time can harm your health.
What causes long-term stress?Long-term stress, or chronic stress, lasts for weeks, months, or longer. As you go about your life, your body is acting as if you're being threatened.
Causes of long-term stress include:
People respond to stress in different ways. If you're stressed for a long time you may notice that you are:
When stress keeps going, your body acts as if you're always in danger. That's a lot of strain that may play a part in developing serious health problems, including:
It's possible to get used to the symptoms of stress and not even realize there's a problem. So when there's a lot of stress in your life, it's important to pay attention to how it affects you so you can do something about it.
How can I manage long-term stress?Simple things that improve your mental health may be helpful in managing long-term stress, such as:
Get help if you're having severe symptoms for 2 weeks or more, including:
Always get help right away if stress is causing you to:
Your health care provider may refer you to a mental health professional such as a psychologist or social worker.
NIH: National Institute of Mental Health
An injury is damage to your body. It is a general term that refers to harm caused by accidents, falls, hits, weapons, and more. In the U.S., millions of people injure themselves every year. These injuries range from minor to life-threatening. Injuries can happen at work or play, indoors or outdoors, driving a car, or walking across the street.
Wounds are injuries that break the skin or other body tissues. They include cuts, scrapes, scratches, and punctured skin. They often happen because of an accident, but surgery, sutures, and stitches also cause wounds. Minor wounds usually aren't serious, but it is important to clean them. Serious and infected wounds may require first aid followed by a visit to your doctor. You should also seek attention if the wound is deep, you cannot close it yourself, you cannot stop the bleeding or get the dirt out, or it does not heal.
Other common types of injuries include: