hypoxia

A coma is a deep state of unconsciousness. An individual in a coma is alive but unable to move or respond to his or her environment. Coma may occur as a complication of an underlying illness, or as a result of injuries, such as brain injury.

A coma rarely lasts more than 2 to 4 weeks. The outcome for coma depends on the cause, severity, and site of the damage. People may come out of a coma with physical, intellectual, and psychological problems. Some people may remain in a coma for years or even decades. For those people, the most common cause of death is infection, such as pneumonia.

NIH: National Institute of Neurological Disorders and Stroke

Heroin is an illegal, very addictive opioid drug. It's made from morphine, which comes from the seedpod of opium poppy plants. These plants grow in Southeast and Southwest Asia, Mexico, and Colombia. Heroin can be a white or brown powder, or a black sticky substance known as black tar heroin.

People inject, sniff, snort, or smoke heroin. Some people mix heroin with crack cocaine, which is called "speedballing." All these ways of taking heroin send it to the brain very quickly, which makes it highly addictive.

People who use heroin report feeling a "rush" (a surge of pleasure). And then they may feel other effects, such as a warm flushing of the skin, dry mouth, and a heavy feeling in the arms and legs. They may also have severe itching, nausea, and vomiting. After these first effects, they will usually be drowsy for several hours, and their breathing will slow down.

People who use heroin over the long term may develop many different health problems. These problems could include liver, kidney, and lung disease, mental disorders, and abscesses.

People who inject the drug also risk getting infectious diseases such as HIV, hepatitis, and bacterial infections of the skin, bloodstream, and heart (endocarditis). They can also get collapsed veins. When a vein collapses, the blood cannot flow through it.

Repeated use of heroin can lead to tolerance. This means users need more and more of the drug to have the same effect. At higher doses over time, the body becomes dependent on heroin. If someone who is dependent on heroin stops using it, they have withdrawal symptoms. These symptoms can include restlessness, muscle and bone pain, diarrhea, vomiting, and cold flashes with goose bumps.

Repeated use of heroin often leads to heroin use disorder, sometimes called addiction. This is more than physical dependence. It's a chronic (long-lasting) brain disorder. When someone has it, they continue to use heroin even though it causes problems in their life. Some examples include health problems and not being able to meet responsibilities at work, school, or home. Getting and using heroin becomes their main purpose in life.

It's possible to overdose on heroin. This happens when a person uses so much heroin that it causes a life-threatening reaction or death. All heroin users are at risk of an overdose because they never know the actual strength of the drug they are taking or what may have been added to it. And people often use heroin along with other drugs or alcohol. This can increase the risk of an overdose.

When people overdose on heroin, their heart rate and breathing slow down. Their breathing may slow do so much that not enough oxygen reaches the brain. This condition is called hypoxia. Hypoxia can lead to a coma, permanent brain damage, or death.

A medicine called naloxone can treat a heroin (or other opioid) overdose if it is given in time. It works by blocking the effects of the opioid on the body. Sometimes more than one dose of the medicine is needed.

There are two forms of naloxone that anyone can use without medical training: nasal spray and injectable. People at risk of an overdose are encouraged to carry naloxone with them. They can buy naloxone at a pharmacy.

Treatments for heroin use disorder include medicines to treat withdrawal symptoms, medicine to block the effects of opioids, and behavioral treatments. Often, a combination of medicine and behavioral treatment works best. People getting treatment for heroin use disorder should work with their health care providers to come up with a treatment plan that fits their needs.

NIH: National Institute on Drug Abuse

Traumatic brain injury (TBI) is a sudden injury that causes damage to the brain. It may happen when there is a blow, bump, or jolt to the head. This is a closed head injury. A TBI can also happen when an object penetrates the skull. This is a penetrating injury.

Symptoms of a TBI can be mild, moderate, or severe. Concussions are a type of mild TBI. The effects of a concussion can sometimes be serious, but most people completely recover in time. More severe TBI can lead to serious physical and psychological symptoms, coma, and even death.

The main causes of TBI depend on the type of head injury:

• Some of the common causes of a closed head injury include
  • Falls. This is the most common cause in adults age 65 and older.
  • Motor vehicle crashes. This is the most common cause in young adults.
  • Sports injuries
  • Being struck by an object
  • Child abuse. This is the most common cause in children under age 4.
  • Blast injuries due to explosions
• Some of the common causes of a penetrating injury include
  • Being hit by a bullet or shrapnel
  • Being hit by a weapon such as a hammer, knife, or baseball bat
  • A head injury that causes a bone fragment to penetrate the skull

Some accidents such as explosions, natural disasters, or other extreme events can cause both closed and penetrating TBI in the same person.

Certain groups are at higher risk of TBI:

• Men are more likely to get a TBI than women. They are also more likely to have serious TBI.
• Adults aged 65 and older are at the greatest risk for being hospitalized and dying from a TBI

The symptoms of TBI depend on the type of injury and how serious the brain damage is.

The symptoms of mild TBI can include:

• A brief loss of consciousness in some cases. However, many people with mild TBI remain conscious after the injury.
• Headache
• Confusion
• Lightheadedness
• Dizziness
• Blurred vision or tired eyes
• Ringing in the ears
• Bad taste in the mouth
• Fatigue or lethargy
• A change in sleep patterns
• Behavioral or mood changes
• Trouble with memory, concentration, attention, or thinking

If you have a moderate or severe TBI, you may have those same symptoms. You may also have other symptoms such as:

• A headache that gets worse or does not go away
• Repeated vomiting or nausea
• Convulsions or seizures
• Not being able to wake up from sleep
• Larger than normal pupil (dark center) of one or both eyes. This is called dilation of the pupil.
• Slurred speech
• Weakness or numbness in the arms and legs
• Loss of coordination
• Increased confusion, restlessness, or agitation

If you have a head injury or other trauma that may have caused a TBI, you need to get medical care as soon as possible. To make a diagnosis, your health care provider:

• Will ask about your symptoms and the details of your injury
• Will do a neurologic exam
• May do imaging tests, such as a CT scan or MRI
• May use a tool such as the Glasgow coma scale to determine how severe the TBI is. This scale measures your ability to open your eyes, speak, and move.
• May do neuropsychological tests to check how your brain is functioning

The treatments for TBI depend on many factors, including the size, severity, and location of the brain injury.

For mild TBI, the main treatment is rest. If you have a headache, you can try taking over-the-counter pain relievers. It is important to follow your health care provider's instructions for complete rest and a gradual return to your normal activities. If you start doing too much too soon, it may take longer to recover. Contact your provider if your symptoms are not getting better or if you have new symptoms.

For moderate to severe TBI, the first thing health care providers will do is stabilize you to prevent further injury. They will manage your blood pressure, check the pressure inside your skull, and make sure that there is enough blood and oxygen getting to your brain.

Once you are stable, the treatments may include:

• Surgery to reduce additional damage to your brain, for example to
  • Remove hematomas (clotted blood)
  • Get rid of damaged or dead brain tissue
  • Repair skull fractures
  • Relieve pressure in the skull
• Medicines to treat the symptoms of TBI and to lower some of the risks associated with it, such as
  • Anti-anxiety medication to lessen feelings of nervousness and fear
  • Anticoagulants to prevent blood clots
  • Anticonvulsants to prevent seizures
  • Antidepressants to treat symptoms of depression and mood instability
  • Muscle relaxants to reduce muscle spasms
  • Stimulants to increase alertness and attention
• Rehabilitation therapies, which can include therapies for physical, emotional, and cognitive difficulties:
  • Physical therapy, to build physical strength, coordination, and flexibility
  • Occupational therapy, to help you learn or relearn how to perform daily tasks, such as getting dressed, cooking, and bathing
  • Speech therapy, to help you to with speech and other communication skills and treat swallowing disorders
  • Psychological counseling, to help you learn coping skills, work on relationships, and improve your emotional well-being
  • Vocational counseling, which focuses on your ability to return to work and deal with workplace challenges
  • Cognitive therapy, to improve your memory, attention, perception, learning, planning, and judgment

Some people with TBI may have permanent disabilities. A TBI can also put you at risk for other health problems such as anxiety, depression, and post-traumatic stress disorder. Treating these problems can improve your quality of life.

There are steps you can take to prevent head injuries and TBIs:

• Always wear your seatbelt and use car seats and booster seats for children
• Never drive under the influence of drugs or alcohol
• Wear a properly fitting helmet when riding a bicycle, skateboarding, and playing sports like hockey and football
• Prevent falls by
  • Making your house safer. For example, you can install railings on the stairs and grab bars in the tub, get rid of tripping hazards, and use window guards and stair safety gates for young children.
  • Improving your balance and strength with regular physical activity

Your brain is the control center of your body. It controls your thoughts, memory, speech, and movement. It regulates the function of many organs. It's part of your nervous system, which also includes your spinal cord and peripheral nerves. The nervous system sends signals between your brain and the rest of the body. Your nerves take in information from your senses and send it to the brain to be processed. Your brain and nerves also communicate to help you move and to control your body's functions.

When the brain is healthy, it works quickly and automatically. But when you have a brain disease, it may affect how well you can function and do your daily activities. Some common brain diseases include:

• Brain tumors, which can press on nerves and affect brain function.
• Degenerative nerve diseases, which can affect many of your body's activities, such as balance, movement, talking, breathing, and heart function. Types include Alzheimer's disease and Parkinson's disease.
• Encephalitis (inflammation in the brain), which can lead to problems such as vision loss, weakness, and paralysis.
• Genetic brain disorders, which are caused by changes in genes (also called variants or mutations). These disorders can affect the development and function of the brain.
• Strokes, which can cause a loss of brain cells and can affect your ability to think clearly.
• Traumatic brain injuries (TBIs), which can affect brain function. They may range from mild to severe. The effects of a TBI may be temporary or permanent.

The symptoms of brain diseases vary widely, depending on the specific problem. In some cases, damage is permanent. In other cases, treatments such as surgery, medicines, or therapies such as physical, occupational, and speech therapies, may cure the disease or improve the symptoms.