Cardiac tamponade in which fluid in the pericardium prevents inflow of blood into the heart (venous return). Constrictive pericarditis, in which the pericardium shrinks and hardens, is similar in presentation. Tension pneumothorax Through increased intrathoracic pressure, bloodflow to the heart is prevented (venous return). Pulmonary embolism is the result of a thromboembolic incident in the blood vessels of the lungs and hinders the return of blood to the heart. Aortic stenosis hinders circulation by obstructing the ventricular outflow tract
Hypertrophic sub-aortic stenosis is overly thick ventricular muscle that dynamically occludes the ventricular outflow tract. Abdominal compartment syndrome defined as an increase in intra-abdominal pressure to > 20 mmHg with organ dysfunction. Increased intraabdominal pressure can be due to sepsis and severe abdominal trauma. This increased pressure reduces blood flow back to the heart, thereby reducing blood flow to the body and resulting in signs and symptoms of shock.Many of the signs of obstructive shock are similar to cardiogenic shock, however treatments differ. Symptoms of obstructive shock include:

Abnormal heart rhythms, often a fast heart rate. Reduced blood pressure. Cool, clammy, mottled skin, often due to low blood pressure and vasoconstriction. Decreased urine output. Distributive
Distributive shock is low blood pressure due to a dilation of blood vessels within the body. This can be caused by systemic infection (septic shock), a severe allergic reaction (anaphylaxis), or spinal cord injury (neurogenic shock). Septic shock is the most common cause of distributive shock. It is caused by an overwhelming systemic infection resulting in vasodilation leading to hypotension.
Signs of septic shock include:
Abnormal heart rhythms, often a fast heart rate
Reduced blood pressure
Decreased urine output
Altered mental status
Anaphylactic shock is caused by a severe anaphylactic reaction to an allergen, antigen, drug, or foreign protein causing the release of histamine which causes widespread vasodilation, leading to hypotension and increased capillary permeability. Signs typically occur after exposure to an allergen and may include:
Skin changes, such as hives, itching, flushing, and swelling. Wheezing and shortness of breath. Abdominal pain, diarrhea, and vomiting. Lightheadedness, confusion, headaches, loss of consciousness. High spinal injuries may cause neurogenic shock, which is commonly classified as a subset of distributive shock. The classic symptoms include a slow heart rate due to loss of cardiac sympathetic tone and warm skin due to dilation of the peripheral blood vessels. (This term can be confused with spinal shock which is a recoverable loss of function of the spinal cord after injury and does not refer to the hemodynamic instability.) Endocrine
Although not officially classified as a subcategory of shock, many endocrinology disturbances in their severe form can result in shock. Hypothyroidism (can be considered a form of cardiogenic shock) in people who are critically ill patients, reduces cardiac output and can lead to hypotension and respiratory insufficiency. Thyrotoxicosis (cardiogenic shock) may induce a reversible cardiomyopathy. Acute adrenal insufficiency (distributive shock) is frequently the result of discontinuing corticosteroid treatment without tapering the dosage. However, surgery and intercurrent disease in patients on corticosteroid therapy without adjusting the dosage to accommodate for increased requirements may also result in this condition.