This initial stage of sepsis is followed by suppression of the immune system.[9] Common signs and symptoms include fever, increased heart rate, increased breathing rate, and confusion.[1] There may also be symptoms related to a specific infection, such as a cough with pneumonia, or painful urination with a kidney infection.[2] The very young, old, and people with a weakened immune system may have no symptoms of a specific infection, and the body temperature may be low or normal instead of having a fever.[2] Severe sepsis causes poor organ function or blood flow.[10] The presence of low blood pressure, high blood lactate, or low urine output may suggest poor blood flow.[10] Septic shock is low blood pressure due to sepsis that does not improve after fluid replacement.[10] Sepsis requires immediate treatment with intravenous fluids and antimicrobials.[1][5] Ongoing care often continues in an intensive care unit.[1] If an adequate trial of fluid replacement is not enough to maintain blood pressure, then the use of medications that raise blood pressure becomes necessary.[1] Mechanical ventilation and dialysis may be needed to support the function of the lungs and kidneys, respectively.[1] A central venous catheter and an arterial catheter may be placed for access to the bloodstream and to guide treatment.[10] Other helpful measurements include cardiac output and superior vena cava oxygen saturation.[10] People with sepsis need preventive measures for deep vein thrombosis, stress ulcers, and pressure ulcers unless other conditions prevent such interventions.[10] Some people might benefit from tight control of blood sugar levels with insulin.[10] The use of corticosteroids is controversial, with some reviews finding benefit,[12][13] and others not.[14] Disease severity partly determines the outcome.[6] The risk of death from sepsis is as high as 30%, while for severe sepsis it is as high as 50%, and septic shock 80%.[15][16][6] Sepsis affected about 49 million people in 2017, with 11 million deaths (1 in 5 deaths worldwide).[17] In the developed world, approximately 0.2 to 3 people per 1000 are affected by sepsis yearly, resulting in about a million cases per year in the United States.[6][7] Rates of disease have been increasing.[10] In addition to symptoms related to the actual cause, people with sepsis may have a fever, low body temperature, rapid breathing, a fast heart rate, confusion, and edema.[18] Early signs include a rapid heart rate, decreased urination, and high blood sugar. Signs of established sepsis include confusion, metabolic acidosis (which may be accompanied by a faster breathing rate that leads to respiratory alkalosis), low blood pressure due to decreased systemic vascular resistance, higher cardiac output, and disorders in blood-clotting that may lead to organ failure.[19] Fever is the most common presenting symptom in sepsis, but fever may be absent in some people such as the elderly or those who are immunocompromised.[20] The drop in blood pressure seen in sepsis can cause lightheadedness and is part of the criteria for septic shock.[21] Oxidative stress is observed in septic shock, with circulating levels of copper and vitamin C being decreased.[22]

In trees, heart rot is a fungal disease that causes the decay of wood at the center of the trunk and branches. Fungi enter the tree through wounds in the bark and decay the heartwood. The diseased heartwood softens, making trees structurally weaker and prone to breakage. Heart rot is a major factor in the economics of logging and the natural growth dynamic of many older forests. Heart rot is prevalent throughout the world affecting all hardwood trees and can be very difficult to prevent. A good indication of heart rot is the presence of mushrooms or fungus conks on the tree. Heart rot is caused by fungi entering the trunk of the tree through wounds in the bark. These wounds are areas of the tree where bare wood is exposed and usually, a result of improper pruning, fire damage, dead branches, insects, or even animal damage. The fungal spores enter the exposed wounds, germinate within the wood tissues, and slowly ingest the heartwood. The infection is a very slow process and can take from months to years, depending on conditions and tree health. An average fungus will advance in the heartwood by 6–8 centimeters per year,[1] and extensive development in the wood tissue is needed before mushrooms or conks are produced.[2][3][4] Pruning focuses on removing dead or diseased branches with minimal damage done to the tree. Branches connect to the trunk and grow from the branch collar. While the branch itself may be dead, the branch collar is still healthy and resistant to disease. It is from the branch collar that a new limb will generate and grow, so it is important not to damage it while pruning. Make clean cuts at the base of the branch adjacent to the branch collar. Small branch stubs (larger than three inches) will inhibit the growth process and provide fungi with ideal growth environments.[10][11] The pathophysiology of septic shock is not entirely understood, but it is known that a key role in the development of severe sepsis is played by an immune and coagulation response to an infection. Both pro-inflammatory and anti-inflammatory responses play a role in septic shock.[7] Septic shock involves a widespread inflammatory response that produces a hypermetabolic effect. This is manifested by increased cellular respiration, protein catabolism, and metabolic acidosis with a compensatory respiratory alkalosis.[8] Most cases of septic shock are caused by gram-positive bacteria,[9] followed by endotoxin-producing gram-negative bacteria, although fungal infections are an increasingly prevalent cause of septic shock.[8] Toxins produced by pathogens cause an immune response; in gram-negative bacteria these are endotoxins, which are bacterial membrane lipopolysaccharides (LPS).