| Medical Dictionary |
A Medical Dictionary of Medical Terminology
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Viral hemorrhagic fevers (VHFs) are a group of illnesses caused by four families of viruses. These include the Ebola and Marburg, Lassa fever, and yellow fever viruses. VHFs have common features: they affect many organs, they damage the blood vessels, and they affect the body's ability to regulate itself. Some VHFs cause mild disease, but some, like Ebola or Marburg, cause severe disease and death.
VHFs are found around the world. Specific diseases are usually limited to areas where the animals that carry them live. For example, Lassa fever is limited to rural areas of West Africa where rats and mice carry the virus.
The risk for travelers is low, but you should avoid visiting areas where there are disease outbreaks. Because there are no effective treatments for some of these viral infections, there is concern about their use in bioterrorism.
Centers for Disease Control and Prevention
A stroke is a medical emergency. There are two types - ischemic and hemorrhagic. Hemorrhagic stroke is the less common type. It happens when a blood vessel breaks and bleeds into the brain. Within minutes, brain cells begin to die. Causes include a bleeding aneurysm, an arteriovenous malformation (AVM), or an artery wall that breaks open.
Symptoms of stroke are:
It is important to treat strokes as quickly as possible. With a hemorrhagic stroke, the first steps are to find the cause of bleeding in the brain and then control it. Surgery may be needed. Post-stroke rehabilitation can help people overcome disabilities caused by stroke damage.
National Institute of Neurological Disorders and Stroke
Ebola, also known as Ebola virus disease (EVD), is a type of hemorrhagic fever. It is a rare and often deadly disease. It can be caused by several different types of Ebola viruses. There are occasional outbreaks of Ebola, and they mostly occur in Africa.
How does Ebola spread?Researchers believe that the virus first spreads from an infected animal to a human. Ebola can then spread from human to human through direct contact with:
When people become infected with Ebola, they do not start developing signs or symptoms right away. They cannot spread Ebola to others until after they develop symptoms.
What are the symptoms of Ebola?The symptoms of Ebola may appear anywhere from 2 to 21 days after exposure to the virus. The average is about 8 to 10 days. The symptoms usually include:
Other symptoms may include a rash, red eyes, and hiccups.
How is Ebola diagnosed?The early symptoms of Ebola are similar to other more common diseases. This makes it difficult to diagnose Ebola in someone who has been infected for only a few days. If a person has the symptoms of Ebola and may have been exposed to the virus, the health care provider can do a blood test for Ebola. It can take a few days after the symptoms start before Ebola shows up in the blood test.
What are the treatments for Ebola?In the United States, there are two approved medicines to treat Ebola that is caused by one specific type of virus (Zaire ebolavirus). These medicines have not been evaluated to treat Ebola caused by other types of Ebola viruses. The medicines are monoclonal antibodies, which are immune system proteins that are created in the lab.
Whether or not there are medicines to treat a case of Ebola, there is supportive care. This type of care can improve the chances of survival, especially when given early. Supportive care includes:
People who recover may still have side effects afterwards, such as fatigue, muscle aches, eye and vision problems, and stomach pain.
Can Ebola be prevented?In the United States, there is one vaccine that has been approved to prevent Ebola caused by one specific type of Ebola virus (Zaire ebolavirus). It may be given to health care providers who will be or may be treating Ebola patients and people who work with live Ebola virus in labs.
If you live in or plan to travel to a region where Ebola virus may be present, you can help protect yourself by avoiding contact with:
Centers for Disease Control and Prevention
Arteriovenous malformations (AVMs) are defects in your vascular system. Your vascular system is your body's network of blood vessels. It includes your:
An AVM is an abnormal tangle of arteries and veins. They are connected to each other, with no capillaries between them. Without the capillaries, the blood flow from the arteries goes directly into the veins at a faster rate than normal. Because of this, the nearby tissue does not get all the oxygen it would normally get. This lack of oxygen can lead to tissue damage and the death of nerve cells and other cells. The fast rate of blood flow can also increase the blood pressure inside the arteries and veins. This can weaken the arteries and veins. A weakened artery or blood vessel could burst or leak blood.
What causes arteriovenous malformations (AVMs)?AVMs are rare. The cause of AVMs is unknown. Most of the time, people are born with them. But sometimes they can appear shortly after birth or later in life.
What are the symptoms of arteriovenous malformations (AVMs)?The symptoms of AVM will depend on where the AVM is located. They can happen anywhere in the body, but they are more common in the brain or spinal cord. Most people with brain or spinal cord AVMs have few, if any, major symptoms. But if a weakened blood vessel bursts, it can spill blood into the brain (called a hemorrhage). Severe hemorrhages can cause a stroke and brain damage.
If an AVM is causing symptoms, they can include:
To find out if you have an AVM, your health care provider:
Treatments for AVMs will depend on factors such as:
The treatment options may include:
NIH: National Institute of Neurological Disorders and Stroke
A stroke happens when there is a loss of blood flow to part of the brain. Your brain cells cannot get the oxygen and nutrients they need from blood, and they start to die within a few minutes. This can cause lasting brain damage, long-term disability, or even death.
If you think that you or someone else is having a stroke, call 911 right away. Immediate treatment may save someone's life and increase the chances for successful rehabilitation and recovery.
What are the types of stroke?There are two types of stroke:
Another condition that's similar to a stroke is a transient ischemic attack (TIA). It's sometimes called a "mini-stroke." TIAs happen when the blood supply to the brain is blocked for a short time. The damage to the brain cells isn't permanent, but if you have had a TIA, you are at a much higher risk of having a stroke.
Who is at risk for a stroke?Certain factors can raise your risk of a stroke. The major risk factors include:
There are also other factors that are linked to a higher risk of stroke, such as:
The symptoms of stroke often happen quickly. They include:
If you think that you or someone else is having a stroke, call 911 right away.
How are strokes diagnosed?To make a diagnosis, your health care provider will:
Treatments for stroke include medicines, surgery, and rehabilitation. Which treatments you get depend on the type of stroke and the stage of treatment. The different stages are:
Acute treatments for ischemic stroke are usually medicines:
Acute treatments for hemorrhagic stroke focus on stopping the bleeding. The first step is to find the cause of bleeding in the brain. The next step is to control it:
Stroke rehabilitation can help you relearn skills you lost because of the damage. The goal is to help you become as independent as possible and to have the best possible quality of life.
Prevention of another stroke is also important, since having a stroke increases the risk of getting another one. Prevention may include heart-healthy lifestyle changes and medicines.
Can strokes be prevented?If you have already had a stroke or are at risk of having a stroke, you can make some heart-healthy lifestyle changes to try to prevent a future stroke:
If these changes aren't enough, you may need medicine to control your risk factors.
NIH: National Institute of Neurological Disorders and Stroke
A bioterrorism attack is the deliberate release of viruses, bacteria, or other germs to cause illness or death. These germs are often found in nature. But they can sometimes be made more harmful by increasing their ability to cause disease, spread, or resist medical treatment.
Biological agents spread through the air, water, or in food. Some can also spread from person to person. They can be very hard to detect. They don't cause illness for several hours or days. Scientists worry that anthrax, botulism, Ebola and other hemorrhagic fever viruses, plague, or smallpox could be used as biological agents.
Biodefense uses medical measures to protect people against bioterrorism. This includes medicines and vaccinations. It also includes medical research and preparations to defend against bioterrorist attacks.
Centers for Disease Control and Prevention
Normally, if you get hurt, your body forms a blood clot to stop the bleeding. For blood to clot, your body needs cells called platelets and proteins known as clotting factors. If you have a bleeding disorder, you either do not have enough platelets or clotting factors or they don't work the way they should.
Bleeding disorders can be the result of other diseases, such as severe liver disease or a lack of vitamin K. They can also be inherited. Hemophilia is an inherited bleeding disorder. Bleeding disorders can also be a side effect of medicines such as blood thinners.
Various blood tests can check for a bleeding disorder. You will also have a physical exam and history. Treatments depend on the cause. They may include medicines and transfusions of blood, platelets, or clotting factor.
A blood clot is a mass of blood that forms when platelets, proteins, and cells in the blood stick together. When you get hurt, your body forms a blood clot to stop the bleeding. After the bleeding stops and healing takes place, your body usually breaks down and removes the blood clot. But sometimes the blood clots form where they shouldn't, your body makes too many blood clots or abnormal blood clots, or the blood clots don't break down like they should. These blood clots can be dangerous and may cause other health problems.
Blood clots can form in, or travel to, the blood vessels in the limbs, lungs, brain, heart, and kidneys. The types of problems blood clots can cause will depend on where they are:
Certain factors can raise your risk of developing blood clots:
The symptoms for blood clots can be different, depending on where the blood clot is:
To find out if you have one or more blood clots, your health care provider:
Treatments for blood clots depend on where the blood clot is located and how severe it is. Treatments may include:
You may be able to help prevent blood clots by:
Some people at high risk may need to take blood thinners to prevent blood clots.
Hantavirus pulmonary syndrome (HPS) is a rare but deadly viral infection. It is spread by mice and rats. They shed the virus in their urine, droppings, and saliva. Tiny droplets with the virus can enter the air. People can get the disease if they breathe infected air or come into contact with rodents or their urine or droppings. You cannot catch it from people.
Early symptoms of HPS include:
Later symptoms include coughing and shortness of breath.
Controlling rodents in and around your house is the best way to prevent infection. If you have been around rodents and have symptoms of fever, deep muscle aches, and severe shortness of breath, see your doctor immediately.
There is no specific treatment, cure, or vaccine for HPS. Patients may do better if it is recognized early and they get medical care in an intensive care unit. They often need to use a breathing machine and have oxygen therapy.
Centers for Disease Control and Prevention
A stroke is a medical emergency. There are two types - ischemic and hemorrhagic. Ischemic stroke is the more common type. It is usually caused by a blood clot that blocks or plugs a blood vessel in the brain. This keeps blood from flowing to the brain. Within minutes, brain cells begin to die. Another cause is stenosis, or narrowing of the artery. This can happen because of atherosclerosis, a disease in which plaque builds up inside your arteries. Transient ischemic attacks (TIAs) occur when the blood supply to the brain is interrupted briefly. Having a TIA can mean you are at risk for having a more serious stroke.
Symptoms of stroke are:
It is important to treat strokes as quickly as possible. Blood thinners may be used to stop a stroke while it is happening by quickly dissolving the blood clot. Post-stroke rehabilitation can help people overcome disabilities caused by stroke damage.
NIH: National Institute of Neurological Disorders and Stroke