Bleeding in the context of "Hypovolemia"

Stroke is a medical condition in which poor blood flow to a part of the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functioning properly.

Signs and symptoms of stroke may include an facial drooping, inability to walk, move or feel on one side of the body, problems understanding or speaking, dizziness, or loss of vision to one side. Signs and symptoms often appear soon after the stroke has occurred. If symptoms last less than 24 hours, the stroke is a transient ischemic attack (TIA), also called a mini-stroke. Hemorrhagic stroke may also be associated with a severe headache. The symptoms of stroke can be permanent. Long-term complications may include pneumonia and loss of bladder control.

A blunt trauma, also known as a blunt force trauma or non-penetrating trauma, is a physical trauma due to a forceful impact without penetration of the body's surface. Blunt trauma stands in contrast with penetrating trauma, which occurs when an object pierces the skin, enters body tissue, and creates an open wound. Blunt trauma occurs due to direct physical trauma or impactful force to a body part. Such incidents often occur with road traffic collisions, assaults, and sports-related injuries, and are common among the elderly who experience falls.

Blunt trauma can lead to a wide range of injuries including contusions, concussions, abrasions, lacerations, internal or external hemorrhages, and bone fractures. The severity of these injuries depends on factors such as the force of the impact, the area of the body affected, and the underlying comorbidities of the affected individual. In some cases, blunt force trauma can be life-threatening and may require immediate medical attention. Blunt trauma to the head and/or severe blood loss are the most likely causes of death due to blunt force traumatic injury.

Hemoptysis or haemoptysis is the discharge of blood or blood-stained mucus through the mouth coming from the bronchi, larynx, trachea, or lungs. In other words, it is the airway bleeding, and does not necessarily involve coughing. This can occur with lung cancer, infections such as tuberculosis, bronchitis, or pneumonia, and certain cardiovascular conditions. Hemoptysis is considered massive at 300 mL (11 imp fl oz; 10 US fl oz). In such cases, there are always severe injuries. The primary danger comes from choking, rather than blood loss.

Dengue fever is a mosquito-borne disease caused by dengue virus, prevalent in tropical and subtropical areas. Most cases of dengue fever are either asymptomatic or manifest mild symptoms. Symptoms typically begin 3 to 14 days after infection. They may include a high fever, headache, vomiting, muscle and joint pains, and a characteristic skin itching and skin rash. Recovery generally takes two to seven days. In a small proportion of cases, the disease develops into severe dengue (previously known as dengue hemorrhagic fever or dengue shock syndrome) with bleeding, low levels of blood platelets, blood plasma leakage, and dangerously low blood pressure.

Dengue is spread by several species of female mosquitoes of the Aedes genus, principally Aedes aegypti. The virus has four confirmed serotypes; infection with one type usually gives lifelong immunity to that type, but only short-term immunity to the others. Subsequent infection with a different type increases the risk of severe complications, so-called antibody-dependent enhancement. The symptoms may resemble those of malaria, influenza, or Zika. Blood tests to confirm the diagnosis including detecting viral RNA, or specific antibodies.

Platelets or thrombocytes (from Ancient Greek θρόμβος (thrómbos) 'clot' and κύτος (kútos) 'cell') are a part of blood whose function (along with the coagulation factors) is to react to bleeding from blood vessel injury by clumping to form a blood clot. Platelets have no cell nucleus; they are fragments of cytoplasm from megakaryocytes which reside in bone marrow or lung tissue, and then enter the circulation. Platelets are found only in mammals, whereas in other vertebrates (e.g. birds, amphibians), thrombocytes circulate as intact mononuclear cells.

One major function of platelets is to contribute to hemostasis: the process of stopping bleeding at the site where the lining of vessels (endothelium) has been interrupted. Platelets gather at the site and, unless the interruption is physically too large, they plug it. First, platelets attach to substances outside the interrupted endothelium: adhesion. Second, they change shape, turn on receptors and secrete chemical messengers: activation. Third, they connect to each other through receptor bridges: aggregation. Formation of this platelet plug (primary hemostasis) is associated with activation of the coagulation cascade, with resultant fibrin deposition and linking (secondary hemostasis). These processes may overlap: the spectrum is from a predominantly platelet plug, or "white clot" to a predominantly fibrin, or "red clot" or the more typical mixture. Berridge adds retraction and platelet inhibition as fourth and fifth steps, while others would add a sixth step, wound repair. Platelets participate in both innate and adaptive intravascular immune responses.

In hematology, thrombocytopenia is a condition characterized by abnormally low levels of platelets (also known as thrombocytes) in the blood. Low levels of platelets in turn may lead to prolonged or excessive bleeding. It is the most common coagulation disorder among intensive care patients and is seen in a fifth of medical patients and a third of surgical patients.

A normal human platelet count ranges from 150,000 to 450,000 platelets/microliter (μL) of blood. Values outside this range do not necessarily indicate disease. One common definition of thrombocytopenia requiring emergency treatment is a platelet count below 50,000/μL. Thrombocytopenia can be contrasted with the conditions associated with an abnormally high level of platelets in the blood – thrombocythemia (when the cause is unknown), and thrombocytosis (when the cause is known).

Postpartum bleeding or postpartum hemorrhage (PPH) is significant blood loss following childbirth. It is the most common cause of maternal death worldwide, disproportionately affecting developing countries. Definitions and criteria for diagnosis are highly variable. PPH is defined by the World Health Organization as "blood loss of 500 ml or more within 24 hours after birth", though signs of shock (insufficient blood flow) have also been used as a definition. Some bleeding after childbirth is normal and is called lochia. It is difficult to distinguish lochia from delayed PPH.

Signs and symptoms of PPH may initially include: an increased heart rate, feeling faint upon standing, and an increased breathing rate. As more blood is lost, the patient may feel cold, blood pressure may drop, and they may become restless or unconscious. In severe cases circulatory collapse, disseminated intravascular coagulation and death can occur. The condition can occur up to twelve weeks following delivery.

Subarachnoid hemorrhage (SAH) is bleeding into the subarachnoid space—the area between the arachnoid membrane and the pia mater surrounding the brain. Symptoms may include a severe headache of rapid onset, vomiting, decreased level of consciousness, fever, weakness, numbness, and sometimes seizures. Neck stiffness or neck pain are also relatively common. In about a quarter of people a small bleed with resolving symptoms occurs within a month of a larger bleed.

SAH may occur as a result of a head injury or spontaneously, usually from a ruptured cerebral aneurysm. Risk factors for spontaneous cases include high blood pressure, smoking, family history, alcoholism, and cocaine use. Generally, the diagnosis can be determined by a CT scan of the head if done within six hours of symptom onset. Occasionally, a lumbar puncture is also required. After confirmation further tests are usually performed to determine the underlying cause.