Blood: Cells, Functions, Diseases, Treatments, Medicines and More

Blood is a specialised tissue that travels in the body all the time. But what is the purpose of its continuity? Well, it functions as a transporting agent that causes the exchange of oxygen and carbon dioxide between cells and the fluid.

Not only this, but it also helps in the absorption of the food within the body (nutrition) and also removes body waste.

• Blood consists of various cells and proteins that make the functioning of the body easy. A human body consists of an average of 5 to 5.5 litres of blood approximately.
• Human blood mainly consists of formed elements and Plasma. Though 55% of blood is plasma and the rest are formed elements.
• The formed elements are of three types ie. fibrinogen, globulins, and albumins.
• Fibrinogen works on the clotting of blood, globulin helps the defence mechanism of blood, and albumin helps in the transport of substances through the blood that further regulates the osmotic balance of the blood.
• Plasma also consists of other dissolved nutrients.
• The main cells present in the blood are RBCs, WBCs, and platelets.
• RBCs help in the transport of oxygen and carbon dioxide within the blood.
• WBCs act as the fighting agents of the blood while platelets are 3.5 to 5 lakh mm3.
• Blood flows through very narrow vessels, i.e., arteries and veins. It's prevented from clotting within the body due to the presence of some clotting factors that are present in an inactive state within the body.
• It is present in the normal state needed for the survival of the body but when something abnormal happens it leads to various blood problems that can affect its transportation as well as its carrying capacity.

• Haemorrhage: When Blood starts oozing out of the blood vessels. Bleeding inside the intestine or due to an accident.
• Hematoma: Internal bleeding causes the assembling of blood within the body, called a hematoma.
• Leukaemia: In blood cancer, WBCs start multiplying abnormally and circulate within the blood. WBCs are infection-fighting agents, but in leukaemia, this property is lost.
• Multiple Myeloma: Blood cancer of plasma cells that further causes anaemia, failure of kidney function, and a high calcium level in the blood.
• Lymphoma: The blood cancer in which WBCs multiply abnormally within the lymph nodes and tissues. Tissues swell and blood functions are disrupted, resulting in organ failure.
• Anaemia: When RBCs count lowers in the blood the condition which arises is called anaemia. It can be clinically seen with the naked eye, such as breathlessness and generalised weakness.
• Hemolytic anaemia: Hemolysis of RBCs causes hemolytic anaemia. In such a case, the person's immune system becomes weak and infections are easily caught by the body.
• Hemochromatosis: Iron is known for its regular oxygen transport function, but when its level increases in the blood, it causes hemochromatosis. This bounded iron gets accumulated in the kidneys pancreas liver causing various complications resulting in hormonal disorders also.
• Sickle cell disease: In SCA, the shape of the RBCs changes from biconcave to sickle disc-like, causing a decrease in oxygen transport, causing pain, uncomfortably in the chest and further organ damage.
• Bacteremia: Bacterial infections in the blood are called bacteremia and require antibiotics for their cure.
• Malaria: The parasitic organism Plasmodium causes infection of RBCs and leads to malaria. Its symptoms include fever, chills, and, if untreated, organ damage.
• Thrombocytopenia: A condition of a decreased level of platelets in the blood. It can cause excessive bleeding.
• Leukopenia: Very low no. of WBCs in the blood. It decreases the potential of the body fighting with external disease-causing agents.Disseminated intravascular coagulation (DIC): When bleeding and clotting of very small blood vessels occurs without intervals, It's present in cases of severe infections and also in cancer.
• Hemophilia: It's due to the absence of blood clotting factors due to which recovering affinity of blood vessels decreases. Blood levels decrease within the body due to excessive loss.
• Hypercoagulable state: Blood being prone to clotting. It can cause heart attack, and heart stroke, due to the clotting of blood and in the lungs, it causes respiration-related problems.
• Polycythemia: Unusual increase in number of RBCs in the blood. It occurs due to low blood oxygen or cancer.Deep venous thrombosis (DVT): it is a disorder in which due to clotting of blood in deep seated viens, They may even stop or reach the lungs, causing a pulmonary embolism.
• Myocardial infarction: A myocardial infarction, often known as a heart attack, occurs when a rapid blood clot forms in either of the coronary arteries, which no longer supplies blood to the heart and so reduces its activity.
• Aplastic Anemia: Anemia in which the bone marrow is unable to produce enough blood cells( RBCs, WBCs, and platelets).
• Thalassemia: It's a genetic disorder that is passed through the blood. The amount/quantity of the Hb (responsible for transporting oxygen) is decreased as a result of the body's requirement for oxygen not being fulfilled.Immune Thrombocytopenic purpura: There's a decreased number of platelets, causing an excess of bleeding and easy bruising.
• Pernicious anaemia: It is an autoimmune disorder in which the body is not able to absorb the required amounts of vitamin B-12, causing a low number of RBCs.
• G6PD deficiency: Ingestion of medications that create oxidant stress on RBCs, such as antimalarials (chloroquine), F sulfonamides, analgesics (phenacetin), and other miscellaneous pharmaceuticals, causes episodes of hemolysis.
• Von Willebrand Disease: autosomal dominant disorder characterized by deficiency or defect of von willebrand factor. it is one of the Most common inherited disorder in which thickness of the blood decreases causing Superficial bleeding in various regions of body ,irregular menstrual symptoms and also chronic Menorrhagia , also having diagnostic finding of Bleeding time prolonged, normal or mildly increased PTT.
• Langerhans Cell Histiocytosis: it is a rare disease of histiocytic infiltration of tissues most commonly bone Occurs commonly in age 1-3, Children show Lytic bone lesions, granulomas found when eosinophilic cells which Can present as pathologic fracture also Skin lesions which Can be presented as rash or ulcerative lesions also Lung cysts/nodules which can show abrupt feeling of lung with extra air pockets
• Amyloidosis: Extracellular tissue deposition of conformationally abnormal protein fibrils, most commonly in beta-pleated sheets. It is a variable multisystem infiltration that includes skin symptoms such as waxy skin, easy bruising, and nodules. Affected individuals also have an enlarged tongue, B muscles, arthropathy, Renal Insufficiency, proteinuria, nephrotic syndrome, and an increased risk of haemorrhage.
• Hypercoagulability: it is the disease which occurs because of lesser activity of a person and also because of various infections relating to blood causing increase in thickness of blood.

• Complete blood count (CBC)- The concentration of RBCs, WBCs, and platelets in the blood is measured. Automated cell counters perform this test.
• Blood smear: A drop of blood sample is topped on a slide and then measured under the microscope to look for Leukemia, anaemia, malaria, and other blood abnormalities that can be seen through these blood smears.
• Blood type: Before blood transfusions, blood samples are tested to see if they are compatible with the patient. Blood types (A, B, AB, and O) are identified by the presence or absence of antigens present on the surface of RBCs.
• Coombs test: This test verifies the presence of antibodies in the body when it is attacked by an antigen. Pregnant women and anaemia patients can undergo this test.
• Blood culture: The test to see if the body has antibodies if it has been exposed to a pathogen.
• Mixing study: test to identify the reason for the thinning of blood affecting its clotting process. To look for its present quality, patients' blood is added to the normal blood sample.
• Bone marrow biopsy: a needle of higher gauge is insert it into the pelvic bone and bone marrow is extracted for performing various analysis.

• Chemotherapy: For Cancer cell killing drugs. Leukemias and lymphomas are given chemotherapy.
• Blood transfusion: Blood donors' RBCs are isolated from their plasma and placed into a tiny bag. Transfusing supersaturated RBCs into a beneficiary compensates for blood loss.
• Platelet transfusion: Platelets from blood donors are isolated from the rest of the blood and deposited in a plastic bag. It is used when platelet levels are extremely low.
• Fresh frozen plasma: The plasma from the volunteer is separated from the blood and stored for preservation. It aids in the reduction of blood clotting and the prevention of coagulation-related haemorrhage.
• Prothrombin Complex: It is a recombinant four factor concentrate (factors II, VII, IX, and X) that is utilised for indications similar to fresh frozen plasma and is quickly becoming a preferred choice.
• Cryoprecipitate: Proteins are isolated from bloodstream and frozen in liquid form. It can replace proteins that are responsible for regulating blood clotting when one‘s levels drop dramatically, as in the case of thalassemia.
• Anticoagulation: thinning the blood and preventing clotting in case of blood clots is a high-risk work. Heparin, enoxaparin and warfarin (Coumadin) are used for their treatment.
• Antiplatelet drugs: Aspirin and clopidogrel interfere with the functioning of the platelet and help in preventing blood clots, therefore, reducing heart attacks and strokes.
• Antibiotics: bactericidal and parasite-killing drugs can treat blood infections.
• Erythropoietin: Kidney produces this hormone which further stimulates RBC production. It can be given to cure the symptoms of anaemia.
• Bloodletting: Problems caused by too much blood (ie. hemochromatosis or polycythemia) occasionally controlled removal of blood is necessary.
• Protein activity assay: It is essential for thrombolytic disorders as well as hemolytic disorders to assess the level of proteins in the blood related with blood transportation and coagulation.

• Aspirin: It is an important drug responsible for inhibition of pain and also acts as an antipyretic and anti-inflammatory drug. It is contraindicated at the time of gastric bleeding or any other form of bleeding.
• Clopidogrel: It is an ADP receptor inhibitor that is given specifically for vascular bleeding and also as a therapeutic drug when standing; it is also contraindicated in the case of a sudden bleed.
• Cilostazol: It is a potent phosphodiesterase inhibitor responsible for a decrease in platelet inhibition when it is given at that time of claudication and also for coronary vasodilation. Side effects include Headache, flushing, heat intolerance, and palpitations
• Heparin: It decreases the activity of thrombin and platelet factor 10. It is used to treat pulmonary embolism and deep vein thrombosis. It is contraindicated at the time of bleeding.
• Apixaban: It is a Factor Xa inhibitor which is given for the treatment of pulmonary embolism, deep venous thrombosis and also reduces the chances of atrial fibrillation.
• Bivalirudin: It is a direct thrombin inhibitor, which is also contraindicated at the time of leading, which is also contraindicated in CKD.
• Warfarin: This type of drug inhibits y-carboxylation of vitamin K dependent clotting factors. They are given as an anticoagulant in the treatment of atrial fibrillation and post vascular stenting (also for deep venous thrombosis and pulmonary embolism).
• Alteplase: It is a potent tissue plasminogen activator, reducing the chances of ischemic stroke and also for the management of pulmonary embolism and myocardial infarction. It is contraindicated at very high risk of bleeding and also having neuronal side effects.
• Cyclosporine: It is one of the most important calcineurin inhibitors vastly used at the time of transplant procedures. It has various side effects which include nephrotoxicity, hypertension, alopecia, gingival hyperplasia, hirsutism, hyperlipidemia, etc.