The diagnosis of DIC is not made on a single laboratory value, but rather the constellation of laboratory markers and a consistent history of an illness known to cause DIC. Laboratory markers consistent with DIC include:

- Characteristic history (this is important because severe liver disease can essentially have the same laboratory findings as DIC)

- Prolongation of the prothrombin time (PT) and the activated partial thromboplastin time (aPTT) reflect the underlying consumption and impaired synthesis of the coagulation cascade.

- Fibrinogen level has initially thought to be useful in the diagnosis of DIC but because it is an acute phase reactant, it will be elevated due to the underlying inflammatory condition. Therefore, a normal (or even elevated) level can occur in over 57% of cases. A low level, however, is more consistent with the consumptive process of DIC.

- A rapidly declining platelet count

- High levels of fibrin degradation products, including D-dimer, are found owing to the intense fibrinolytic activity stimulated by the presence of fibrin in the circulation.

- The peripheral blood smear may show fragmented red blood cells (known as schistocytes) due to shear stress from thrombi. However, this finding is neither sensitive nor specific for DIC

A diagnostic algorithm has been proposed by the International Society of Thrombosis and Haemostasis. This algorithm appears to be 91% sensitive and 97% specific for the diagnosis of overt DIC. A score of 5 or higher is compatible with DIC and it is recommended that the score is repeated daily, while a score below 5 is suggestive but not affirmative for DIC and it is recommended that it is repeated only occasionally: It has been recommended that a scoring system be used in the diagnosis and management of DIC in terms of improving outcome.

- Presence of an underlying disorder known to be associated with DIC (no=0, yes=2)

- Global coagulation results

- Platelet count (>100k = 0, <100 = 1, <50 = 2)

- Fibrin degradation products such as D-Dimer (no increase = 0, moderate increase = 2, strong increase = 3)

- Prolonged prothrombin time (3 sec = 1, >6 sec = 2)

- Fibrinogen level (> 1.0g/L = 0; < 1.0g/L = 1)

Prognosis varies depending on the underlying disorder, and the extent of the intravascular thrombosis (clotting). The prognosis for those with DIC, regardless of cause, is often grim: Between 20% and 50% of patients will die. DIC with sepsis (infection) has a significantly higher rate of death than DIC associated with trauma.

Treatment of asymptomatic congenital dysfibrinogenemia depends in part on the expectations of developing bleeding and/or thrombotic complications as estimated based on the history of family members with the disorder and, where available, determination of the exact mutation causing the disorder plus the propensity of the particular mutation type to develop these complications. In general, individuals with this disorder require regular follow-up and multidiscipline management prior to surgery, pregnancy, and giving childbirth. Women with the disorder appear to have an increased rate of miscarriages and all individuals with fibrinogen activity in clotting tests below 0.5 grams/liter are prone to bleeding and spontaneous abortions. Women with multiple miscarriages and individuals with excessively low fibrinogen activity levels should be considered for prophylaxis therapy with fibrinogen replacement during pregnancy, delivery, and/or surgery.

Diagnosis of inherited hypoprothrombinemia, relies heavily on a patient's medical history, family history of bleeding issues, and lab exams performed by a hematologist. A physical examination by a general physician should also be performed in order to determine whether the condition is congenital or acquired, as well as ruling out other possible conditions with similar symptoms. For acquired forms, information must be taken regarding current diseases and medications taken by the patient, if applicable.

Lab tests that are performed to determine diagnosis:

1. Factor Assays: To observe the performance of specific factors (II) to identify missing/poorly performing factors. These lab tests are typically performed first in order to determine the status of the factor.

2. Prothrombin Blood Test: Determines if patient has deficient or low levels of Factor II.

3. Vitamin K1 Test: Performed to evaluate bleeding of unknown causes, nosebleeds, and identified bruising. To accomplish this, a band is wrapped around the patient's arm, 4 inches above the superficial vein site in the elbow pit. The vein is penetrated with the needle and amount of blood required for testing is obtained. Decreased vitamin K levels are suggestive of hypoprothrombinemia. However, this exam is rarely used as a Prothrombin Blood Test is performed beforehand.

In a study of 189 individuals diagnosed with congenital dysfibrinogenemia, ~33% were asymptomatic, ~47% experienced episodic bleeding, and ~20% experienced episodic thromboses. Due to the rareness of this disorder, treatment of individuals with these presentations are based primarily on case reports, guidelines set by the United Kingdom, and expert opinions rather than controlled clinical studies.

A 28 month old girl, showed symptoms from 8 months of age and consisted of complaints of painful bruises over lower limbs, and disturbed, painful sleep at night. Family history revealed older brother also suffered similar problems and died at age of two years possibly due to bleeding - no diagnosis was confirmed. Complete blood count and blood smear was determined as normal. No abnormality in fibrinogen, liver function test, and bleeding time. However, prothrombin levels were less than 1% so patient was transfused with fresh frozen plasma (FFP). Post transfusion methods, patient is now 28 months old and living healthy life. The only treatment that is needed to date is for the painful bruises, which the patient is given FFP every 5-6 weeks.

Twelve day old boy admitted for symptoms consisting of blood stained vomiting and dark colored stool. Upon admission into hospital, patient received vitamin K and FFP transfusion. No family history of similarity in symptoms that were presented. At 40 days old, patient showed symptoms of tonic posturing and constant vomiting. CT scan revealed subdural hemorrhage, and other testing showed low hb levels of 7%, platelets at 3.5 lakhs/cu mm. PT examination was 51 seconds and aPTT at 87 seconds. Prothrombin activity levels were less than 1%. All other exams revealed no abnormalities. Treatment methods included vitamin K and FFP, as well as ventilator support and packed red blood cell transfusion (PRBC). At half a year of age, condition consisted of possible poor neurological outcome secondary to CNS bleeding. Treatment of very frequent transfusion was needed for patient.

Recent study illustrated a patient with 2 weeks of continuous bleeding, with presence of epistaxis, melena, hematuria, and pruritic rash with no previous bleeding history. Vitals were all within normal range, however, presence of ecchymoses was visible in chest, back and upper areas. Lab exams revealed prolonged prothrombin time (PT) of 34.4 and acquired partial thromboplastin time (aPTT) of 81.7, as well as elevated liver function tests. Discontinuation of atorvastatin, caused liver enzymes to go back to normal. Treatment of vitamin K, antibiotics, and fresh frozen plasma (FFP) did not have an impact on coagulopathy. Mixing of PT and aPTT was performed in order to further evaluate coagulopathy and revealed no correction. Factor activity assays were performed to determine the presence of a specific one. Testing revealed that factor II activity could not be quantified. Further studies showed that acquired factor II inhibitor was present without the lupus anticoagulant, with no clear cause associated with the condition. Aimed to control bleeding and getting rid of the inhibitor through directly treating the underlying disease or through immunosuppressive therapy. Corticosteroids and intravenous immunoglobulin improved the PT and aPTT. Did not improve bleeding conditions until treatment of transfusion with activated PCC. Treatment of inhibitor required Rituximab, which was shown to increase factor II levels to 264%. Study shows that when a patient with no history of coagulopathy presents themselves with hemorrhagic diathesis, direct testing of a factor II inhibitor should be performed initially.

One area of treatment is managing people with major bleeding in a critical setting, like an emergency department. In these situations, the common treatment is transfusing a combination of red cells with one of the following options:

- Blood plasma

- Prothrombin complex concentrate, factor XIII, and fibrinogen

- Fibrinogen with tranexamic acid

The use of tranexamic acid is the only option that is currently supported by a large, randomized, controlled clinical trial, and is given to people with major bleeding after trauma. There are several possible risks to treating coagulopathies, such as transfusion-related acute lung injury, acute respiratory distress syndrome, multiple organ dysfunction syndrome, major hemorrhage, and venous thromboembolism.

If someone has coagulopathy, their health care provider may help them manage their symptoms with medications or replacement therapy. In replacement therapy, the reduced or absent clotting factors are replaced with proteins derived from human blood or created in the laboratory. This therapy may be given either to treat bleeding that has already begun or to prevent bleeding from occurring.

The diagnosis of hypofibrinogenemia is indicated in individuals who have low levels (<1.5 gram/liter) of plasma fibrinogen as determined by both immunological (e.g. immunoelectrophoresis and (i.e. able to be clotted) methods. The ratio of immunological to functional fibrinogen masses should be ~1.0 as assayed with partial thromboplastin time, activated partial thromboplastin time, thrombin time, and reptilase time tests. These tests are used to distinguish hypofibrinogenemia from hypodysfibrinogenemia, a typically more severe disorder in which plasma fibrinogen levels are low and this fibrinogen includes at least in part dysfunctional fibrinogen. Immunological/functional fibrinogen ratios for the plasma of individuals with hypodysfibrinogenemia for all the cited tests are usually <0.7. Where available, further analyses are recommended; these include analyses of the fibrinogen genes and protein chains for mutations and specialized studies of individuals in vitro induced blood clots for stability and susceptibility to lyses.

The diagnosis of fibrin storage disease requires liver biopsy and the finding of immunologically detectable fibrinogen inclusion bodies in hepatocytes.

Laboratory tests for thrombocytopenia might include full blood count, liver enzymes, kidney function, vitamin B levels, folic acid levels, erythrocyte sedimentation rate, and peripheral blood smear. If the cause for the low platelet count remains unclear, a bone marrow biopsy is usually recommended to differentiate cases of decreased platelet production from cases of peripheral platelet destruction.

Thrombocytopenia in hospitalized alcoholics may be caused by spleen enlargement, folate deficiency, and, most frequently, the direct toxic effect of alcohol on production, survival time, and function of platelets. Platelet count begins to rise after 2 to 5 days' abstinence from alcohol. The condition is generally benign, and clinically significant hemorrhage is rare.

In severe thrombocytopenia, a bone marrow study can determine the number, size and maturity of the megakaryocytes. This information may identify ineffective platelet production as the cause of thrombocytopenia and rule out a malignant disease process at the same time.

Anti-platelet autoantibodies in a pregnant woman with ITP will attack the patient's own platelets and will also cross the placenta and react against fetal platelets. Therefore, ITP is a significant cause of fetal and neonatal immune thrombocytopenia. Approximately 10% of newborns affected by ITP will have platelet counts <50,000/uL and 1% to 2% will have a risk of intracerebral hemorrhage comparable to infants with neonatal alloimmune thrombocytopenia (NAIT).

No lab test can reliably predict if neonatal thrombocytopenia will occur. The risk of neonatal thrombocytopenia is increased with:

- Mothers with a history of splenectomy for ITP

- Mothers who had a previous infant affected with ITP

- Gestational (maternal) platelet count less than 100,000/uL

It is recommended that pregnant women with thrombocytopenia or a previous diagnosis of ITP should be tested for serum antiplatelet antibodies. A woman with symptomatic thrombocytopenia and an identifiable antiplatelet antibody should be started on therapy for their ITP which may include steroids or IVIG. Fetal blood analysis to determine the platelet count is not generally performed as ITP-induced thrombocytopenia in the fetus is generally less severe than NAIT. Platelet transfusions may be performed in newborns, depending on the degree of thrombocytopenia. It is recommended that neonates be followed with serial platelet counts for the first few days after birth.,

The diagnosis of hemophilia A may be suspected as coagulation testing reveals an increased PTT in the context of a normal PT and bleeding time. PTT tests are the first blood test done when haemophilia is indicated. However, the diagnosis is made in the presence of very low levels of Factor VIII. A family history is frequently present, although not essential. Recently, genetic testing has been made available to determine an individual's risk of attaining or passing on hemophilia. Diagnosis of haemophilia A also includes a severity level which can range from mild to severe based on the amount of active and functioning factor VIII detected in the blood. Factor VIII levels do not typically change throughout an individual's life. Severe haemophilia A is the most common form occurring in the majority of affected people. Individuals with mild haemophilia often experience few or no bleeding episodes except in the case of serious trauma (i.e. tooth extraction, or surgery).

A pregnant woman with a history of haemophilia in her family can test for the haemophilia gene. Such tests include:

- chorionic villus sampling (CVS) – a small sample of the placenta is removed from the womb and tested for the haemophilia gene, usually during weeks 11-14 of pregnancy

- amniocentesis – a sample of amniotic fluid is taken for testing, usually during weeks 15-20 of pregnancy

There's a small risk of these procedures causing problems such as miscarriage or premature labour, so the woman may discuss this with the doctor in charge of her care.

Two of the most common differential diagnoses are haemophilia B which is a deficiency in Factor IX and von Willebrand Disease which is a deficiency in von Willebrand factor (needed for the proper functioning of Factor VIII), haemophilia C is also a possible, differential diagnosis.

Genetic testing and counselling are available to help determine the risk of passing the condition onto a child. This may involve testing a sample of tissue or blood to look for signs of the genetic mutation that causes haemophilia.

Recommended treatment of asymptomatic congenital hypofibrinogenemia depends in part on the expectations of developing bleeding and/or thrombotic complications as indicated by the personal history of the afflicted individual and family members. Where possible, determination of the exact mutation causing the disorder and the propensity of this mutation type to develop these complications may be helpful. Individuals with fibrinogen levels >1.0 gram/liter typically do not develop bleeding or thrombosis episodes. Individuals with fibrinogen levels of 0.5-1.0 grams/liter require fibrinogen supplementation preferably with a plasma-derived fibrinogen concentrate to maintain fibrinogen levels of >1 gram/liter prior to major surgery. Individuals with fibrinogen levels of 1 to 2 gram/liter at the end of pregnancy and during the postpartum period; b) > 1 gram/liter prior to major surgery; c) > 0.5 to 1 gram/liter during the first two trimesters of pregnancy; and d) >0.5 gram/liter prior to minor surgery. Tranexamic acid may be used in place of fibrinogen supplementation as prophylactic treatment prior to minor surgery and to treat minor bleeding episodes.

The diagnosis of ITP is a process of exclusion. First, it has to be determined that there are no blood abnormalities other than a low platelet count, and no physical signs other than bleeding. Then, secondary causes (5–10 percent of suspected ITP cases) should be excluded. Such secondary causes include leukemia, medications (e.g., quinine, heparin), lupus erythematosus, cirrhosis, HIV, hepatitis C, congenital causes, antiphospholipid syndrome, von Willebrand factor deficiency, onyalai and others. In approximately one percent of cases, autoimmune hemolytic anemia and ITP coexist, a condition referred to as Evans syndrome, a condition that points to CLL as a possible cause.

Despite the destruction of platelets by splenic macrophages, the spleen is normally not enlarged. In fact, an enlarged spleen should lead to a search for other possible causes for the thrombocytopenia. Bleeding time is usually prolonged in ITP patients. However, the use of bleeding time in diagnosis is discouraged by the American Society of Hematology practice guidelines and a normal bleeding time does not exclude a platelet disorder.

Bone marrow examination may be performed on patients over the age of 60 and those who do not respond to treatment, or when the diagnosis is in doubt. On examination of the marrow, an increase in the production of megakaryocytes may be observed and may help in establishing a diagnosis of ITP. An analysis for anti-platelet antibodies is a matter of clinician's preference, as there is disagreement on whether the 80 percent specificity of this test is sufficient to be clinically useful.

Treatment of thrombotic thrombocytopenic purpura (TTP) is a medical emergency, since the associated hemolytic anemia and platelet activation can lead to renal failure and changes in the level of consciousness. Treatment of TTP was revolutionized in the 1980s with the application of plasmapheresis. According to the Furlan-Tsai hypothesis, this treatment works by removing antibodies against the von Willebrand factor-cleaving protease ADAMTS-13. The plasmapheresis procedure also adds active ADAMTS-13 protease proteins to the patient, restoring a normal level of von Willebrand factor multimers. Patients with persistent antibodies against ADAMTS-13 do not always manifest TTP, and these antibodies alone are not sufficient to explain how plasmapheresis treats TTP.

People may be diagnosed after prolonged and/or recurring bleeding episodes. Children and adults may also be diagnosed after profuse bleeding after a trauma or tooth extraction. Ultimately, a laboratory diagnosis is usually required. This would utilize platelet aggregation studies and flow cytometry.

Hypodysfibrinogenemia is usually diagnosed in individuals who: have a history of abnormal bleeding or thrombosis or are a close blood relative of such an individual. Initial laboratory findings include a decrease in serum fibrinogen mass levels as measured by immunoassay plus a reduction in inducible blood clot formation so that the ratio of functionally-detected fibrinogen mass (i.e. detected in induced clots) to immunoassay-detected fibrinogen mass is abnormally low, i.e. <0.7. This contrast with individuals with congenital dysfibrinogenemia who exhibit normal levels of fibrinogen as measured by immunoassay but low functionally-detected to immunoassay-detected fibrinogen mass ratios, i.e. <0.7. Where available, specialized laboratories can conduct studies to define the exact gene mutation(s) and fibrinogen abnormalities underlying the disorder.

Hydroxycarbamide and anagrelide are contraindicated during pregnancy and nursing. Essential thrombocytosis can be linked with a three-fold increase in risk of miscarriage. Throughout pregnancy, close monitoring of the mother and fetus is recommended. Low-dose low molecular weight heparin (e.g. enoxaparin) may be used. For life-threatening complications, the platelet count can be reduced rapidly using platelet apheresis, a procedure that removes platelets from the blood and returns the remainder to the patient.

When vWD is suspected, blood plasma of a patient must be investigated for quantitative and qualitative deficiencies of vWF. This is achieved by measuring the amount of vWF in a vWF antigen assay and the functionality of vWF with a glycoprotein (GP)Ib binding assay, a collagen binding assay, or a ristocetin cofactor activity (RiCof) or ristocetin induced platelet agglutination (RIPA) assays. Factor VIII levels are also performed because factor VIII is bound to vWF which protects the factor VIII from rapid breakdown within the blood. Deficiency of vWF can then lead to a reduction in factor VIII levels, which explains the elevation in PTT. Normal levels do not exclude all forms of vWD, particularly type 2, which may only be revealed by investigating platelet interaction with subendothelium under flow, a highly specialized coagulation study not routinely performed in most medical laboratories. A platelet aggregation assay will show an abnormal response to ristocetin with normal responses to the other agonists used. A platelet function assay may give an abnormal collagen/epinephrine closure time, and in most cases, a normal collagen/ADP time. Type 2N may be considered if factor VIII levels are disproportionately low, but confirmation requires a "factor VIII binding" assay. Additional laboratory tests that help classify sub-types of vWD include von-willebrand multimer analysis, modified ristocetin induced platelet aggregation assay and vWF propeptide to vWF antigen ratio propeptide. In cases of suspected acquired von-Willebrand syndrome, a mixing study study (analysis of patient plasma along with pooled normal plasma/PNP and a mixture of the two tested immediately, at one hour, and at two hours) should be performed. Detection of vWD is complicated by vWF being an acute phase reactant with levels rising in infection, pregnancy, and stress.

Other tests performed in any patient with bleeding problems are a complete blood count-CBC (especially platelet counts), activated partial thromboplastin time-APTT, prothrombin time with International Normalized Ratio-PTINR, thrombin time-TT, and fibrinogen level. Testing for factor IX may also be performed if hemophilia B is suspected. Other coagulation factor assays may be performed depending on the results of a coagulation screen. Patients with von Willebrand disease typically display a normal prothrombin time and a variable prolongation of partial thromboplastin time.

The testing for vWD can be influenced by laboratory procedures. Numerous variables exist in the testing procedure that may affect the validity of the test results and may result in a missed or erroneous diagnosis. The chance of procedural errors are typically greatest during the preanalytical phase (during collecting storage and transportation of the specimen) especially when the testing is contracted to an outside facility and the specimen is frozen and transported long distances. Diagnostic errors are not uncommon, and the rate of testing proficiency varies amongst laboratories, with error rates ranging from 7 to 22% in some studies to as high as 60% in cases of misclassification of vWD subtype. To increase the probability of a proper diagnosis, testing should be done at a facility with immediate on-site processing in a specialized coagulation laboratory.

The diagnosis for hemophilia B can be done via the following tests/methods:

- Coagulation screening test

- Bleeding scores

- Coagulation factor assays

When a problem of fibrinogen is suspected, the following tests can be ordered:

- PT

- PTT

- Fibrinogen level in blood (total and clottable)

- Reptilase time

- Thrombin time

Blood fibrinogen levels of less than 0.1 g/L and prolonged bleeding test times are indicators of an individual having afibrinogenemia.

There has been no general recommendation for treatment of patients with Giant Platelet Disorders, as there are many different specific classifications to further categorize this disorder which each need differing treatments. Platelet transfusion is the main treatment for people presenting with bleeding symptoms. There have been experiments with DDAVP (1-deamino-8-arginine vasopressin) and splenectomy on people with Giant platelet disorders with mixed results, making this type of treatment contentious.