question: Why does pneumonia sometimes cause your body temperature to go down?
comment: Are you sure you mean low body temperature, because when you feel cold it's because you have a fever. If your body temperature drops your surroundings will feel hot. I guess it can lower body temperature in other areas of the body not near the infection site, because of the lowered blood supply.
passages: People who are on mechanical ventilation are often sedated and are rarely able to communicate. As such, many of the typical symptoms of pneumonia will either be absent or unable to be obtained. The most important signs are fever or low body temperature, new purulent sputum, and hypoxemia (decreasing amounts of oxygen in the blood). However, these symptoms may be similar for tracheobronchitis.
  
  Section::::Cause.
  
  Section::::Cause.:Risk factors.
   Bacteria typically enter the lung with inhalation, though they can reach the lung through the bloodstream if other parts of the body are infected. Often, bacteria live in parts of the upper respiratory tract and are continuously being inhaled into the alveoli, the cavities deep in the lungs where gas exchange takes place. Once inside the alveoli, bacteria travel into the spaces between the cells and also between adjacent alveoli through connecting pores. This invasion triggers the immune system to respond by sending white blood cells responsible for attacking microorganisms (neutrophils) to the lungs. The neutrophils engulf and kill the offending organisms but also release cytokines that result in a general activation of the immune system. This results in the fever, chills, and fatigue common in bacterial and fungal pneumonia. The neutrophils, bacteria, and fluid leaked from surrounding blood vessels fill the alveoli and result in impaired oxygen transportation.
   Sepsis is a potential complication of pneumonia but occurs usually in people with poor immunity or hyposplenism. The organisms most commonly involved are "Streptococcus pneumoniae", "Haemophilus influenzae", and "Klebsiella pneumoniae". Other causes of the symptoms should be considered such as a myocardial infarction or a pulmonary embolism.
  
  Section::::Epidemiology.
   People with infectious pneumonia often have a productive cough, fever accompanied by shaking chills, shortness of breath, sharp or stabbing chest pain during deep breaths, and an increased rate of breathing. In elderly people, confusion may be the most prominent sign.
   Respiratory alkalosis ("Pa" CO < 35 mmHg) occurs when there is too little carbon dioxide in the blood. This may be due to hyperventilation or else excessive breaths given via a mechanical ventilator in a critical care setting. The action to be taken is to calm the person and try to reduce the number of breaths being taken to normalize the pH. The respiratory pathway tries to compensate for the change in pH in a matter of 2–4 hours. If this is not enough, the metabolic pathway takes place.
  
  Under normal conditions, the Henderson–Hasselbalch equation will give the blood pH
   BULLET::::- Avoid confusion with bronchiolitis obliterans, which may not be visualized in every case of this disease.
  
  BULLET::::- Avoid confusion with constrictive bronchiolitis
  
  BULLET::::- Emphasize the cryptogenic nature of the disease
  
  Section::::Signs and symptoms.
   Pneumonia caused by "Yersinia pestis" is usually called pneumonic plague.
  
  Section::::Signs and symptoms.
  
  BULLET::::- Pneumonia
  
  BULLET::::- Fever
  
  BULLET::::- Rigors
  
  BULLET::::- Cough
  
  BULLET::::- Runny nose (either direct bacterial pneumonia or accompanied by primary viral pneumonia)
  
  BULLET::::- Dyspnea – shortness of breath
  
  BULLET::::- Chest pain
  
  BULLET::::- Shaking chills
  
  BULLET::::- Pneumococcal pneumonia can cause coughing up of blood, or hemoptysis, characteristically associated with "rusty" sputum
  
  Section::::Pathophysiology.
   The classic presentation of COP is the development of nonspecific systemic (e.g., fevers, chills, night sweats, fatigue, weight loss) and respiratory (e.g. difficulty breathing, cough) symptoms in association with filling of the lung alveoli that is visible on chest x-ray. This presentation is usually so suggestive of an infection that the majority of patients with COP have been treated with at least one failed course of antibiotics by the time the true diagnosis is made.
  
  Section::::Causes.
  
  BULLET::::- Pulmonary infection by bacteria, viruses and parasites
  
  BULLET::::- Drugs: antineoplastic drugs, erlotinib, amiodarone
  
  BULLET::::- Toxic fumes
  
  BULLET::::- Ionizing radiations
  
  BULLET::::- Inflammatory diseases
   Pneumonia has been a common disease throughout human history. The word is from Greek πνεύμων (pneúmōn) meaning "lung". The symptoms were described by Hippocrates (c. 460–370 BC): "Peripneumonia, and pleuritic affections, are to be thus observed: If the fever be acute, and if there be pains on either side, or in both, and if expiration be if cough be present, and the sputa expectorated be of a blond or livid color, or likewise thin, frothy, and florid, or having any other character different from the common... When pneumonia is at its height, the case is beyond remedy if he is not purged, and it is bad if he has dyspnoea, and urine that is thin and acrid, and if sweats come out about the neck and head, for such sweats are bad, as proceeding from the suffocation, rales, and the violence of the disease which is obtaining the upper hand." However, Hippocrates referred to pneumonia as a disease "named by the ancients". He also reported the results of surgical drainage of empyemas. Maimonides (1135–1204 AD) observed: "The basic symptoms that occur in pneumonia and that are never lacking are as follows: acute fever, sticking pleuritic pain in the side, short rapid breaths, serrated pulse and cough." This clinical description is quite similar to those found in modern textbooks, and it reflected the extent of medical knowledge through the Middle Ages into the 19th century.
   Fungi typically enter the lung with inhalation of their spores, though they can reach the lung through the bloodstream if other parts of the body are infected. Also, fungal pneumonia can be caused by reactivation of a latent infection. Once inside the alveoli, fungi travel into the spaces between the cells and also between adjacent alveoli through connecting pores. This invasion triggers the immune system to respond by sending white blood cells responsible for attacking microorganisms (neutrophils) to the lungs. The neutrophils engulf and kill the offending organisms but also release cytokines which result in a general activation of the immune system. This results in the fever, chills, and fatigue common in bacterial and fungal pneumonia. The neutrophils and fluid leaked from surrounding blood vessels fill the alveoli and result in impaired oxygen transportation.
   "Pneumocystis" pneumonia is an important disease of immunocompromised humans, particularly patients with HIV, but also patients with an immune system that is severely suppressed for other reasons, for example, following a bone marrow transplant. In humans with a normal immune system, it is an extremely common silent infection.
   Pneumonia front
  
  The term Pneumonia front, first coined by Milwaukee Weather Bureau Office in the 1960s, is used to describe a rare meteorological phenomenon observed on the western Lake Michigan, USA, shoreline during the warm season. These fronts are defined as lake-modified synoptic scale cold fronts that result in one-hour temperature drops of 16 °F (8.9 °C) or greater.
   They do not necessarily have to be synoptic, or large scale, cold fronts. Very often in the spring to early summer the temperature difference between the cold lake waters and the warmer air over land can be as much as 35-40 °F. Under weak prevailing winds, a density current can often develop in the form of a lake breeze that moves from that water to the adjacent shoreline and several miles inland. This "lake-breeze cold front" can drop temperature in places like Chicago, Milwaukee and Green Bay significantly as they cross the area. There has been many a spring day at Wrigley Field that surprises people who may have travelled from an inland location toward the shore to take in an afternoon game, only to feel the effects of the "pneumonia front" as that cold blast of air comes through.
   Physical examination may sometimes reveal low blood pressure, high heart rate, or low oxygen saturation. The respiratory rate may be faster than normal, and this may occur a day or two before other signs. Examination of the chest may be normal, but it may show decreased chest expansion on the affected side. Harsh breath sounds from the larger airways that are transmitted through the inflamed lung are termed bronchial breathing and are heard on auscultation with a stethoscope. Crackles (rales) may be heard over the affected area during inspiration. Percussion may be dulled over the affected lung, and increased, rather than decreased, vocal resonance distinguishes pneumonia from a pleural effusion.
   BULLET::::- Pneumonia is an infection of the lung parenchyma, which can be caused by both viruses and bacteria. Cytokines and fluids are released into the alveolar cavity and/or interstitium in response to infection, causing the effective surface area of gas exchange in the lungs to be reduced. If this happens to such a degree that the patient cannot draw enough oxygen from his or her environment to maintain cellular respiration, then the victim may need supplemental oxygen.
   Bacteria and fungi typically enter the lungs through the inhalation of water droplets, although they can reach the lung through the bloodstream if an infection is present and often live in the respiratory tract. In the alveoli, bacteria and fungi travel into the spaces between cells and adjacent alveoli through connecting pores. The immune system responds by releasing neutrophil granulocytes, white blood cells responsible for attacking microorganisms, into the lungs. The neutrophils engulf and kill the microorganisms, releasing cytokines which activate the entire immune system. This response causes fever, chills and fatigue, common symptoms of CAP. The neutrophils, bacteria and fluids leaked from surrounding blood vessels fill the alveoli, impairing oxygen transport. Bacteria may travel from the lung to the bloodstream, causing septic shock (very low blood pressure which damages the brain, kidney, and heart).
   The normal range for pH is 7.35–7.45. As the pH decreases (< 7.35), it implies acidosis, while if the pH increases ( 7.45) it implies alkalosis. In the context of arterial blood gases, the most common occurrence will be that of respiratory acidosis. Carbon dioxide is dissolved in the blood as carbonic acid, a weak acid; however, in large concentrations, it can affect the pH drastically. Whenever there is poor pulmonary ventilation, the carbon dioxide levels in the blood are expected to rise. This leads to a rise of carbonic acid, leading to a decrease in pH. The first buffer of pH will be the plasma proteins, since these can accept some H ions to try to maintain acid-base homeostasis. As carbon dioxide concentrations continue to increase ("Pa"CO  45 mmHg), a condition known as respiratory acidosis occurs. The body tries to maintain homeostasis by increasing the respiratory rate, a condition known as tachypnea. This allows much more carbon dioxide to escape the body through the lungs, thus increasing the pH by having less carbonic acid. If a person is in a critical setting and intubated, one must increase the number of breaths mechanically.
   Ventilator-associated pneumonia occurs in people breathing with the help of mechanical ventilation. Ventilator-associated pneumonia is specifically defined as pneumonia that arises more than 48 to 72 hours after endotracheal intubation.
  
  Section::::Diagnosis.:Differential diagnosis.
   Patients with symptoms of CAP require evaluation. Diagnosis of pneumonia is made clinically, rather than on the basis of a particular test. Evaluation begins with a physical examination by a health provider, which may reveal fever, an increased respiratory rate (tachypnea), low blood pressure (hypotension), a fast heart rate (tachycardia) and changes in the amount of oxygen in the blood. Palpating the chest as it expands and tapping the chest wall (percussion) to identify dull, non-resonant areas can identify stiffness and fluid, signs of CAP. Listening to the lungs with a stethoscope (auscultation) can also reveal signs associated with CAP. A lack of normal breath sounds or the presence of crackles can indicate fluid consolidation. Increased vibration of the chest when speaking, known as tactile fremitus, and increased volume of whispered speech during auscultation can also indicate fluid.
   The symptoms of pneumococcal pneumonia can occur suddenly, typically presenting as a severe chill, later including a severe fever, cough, shortness of breath, rapid breathing, and chest pains. Other symptoms like nausea, vomiting, headache, fatigue, and muscle aches could also accompany the original symptoms. Sometimes the coughing can produce rusty or blood-streaked sputum. In 25% of cases, a parapneumonic effusion may occur. Chest X-rays will typically show lobar consolidation or patchy infiltrates.
   New or progressive infiltrate on the chest X-ray with one of the following:
  
  BULLET::::- Fever  37.8 °C (100 °F)
  
  BULLET::::- Purulent sputum
  
  BULLET::::- Leukocytosis  10,000 cells/μl
  
  In an elderly person, the first sign of hospital-acquired pneumonia may be mental changes or confusion.
  
  Other symptoms may include:
  
  BULLET::::- A cough with greenish or pus-like phlegm (sputum)
  
  BULLET::::- Fever and chills
  
  BULLET::::- General discomfort, uneasiness, or ill feeling (malaise)
  
  BULLET::::- Loss of appetite
  
  BULLET::::- Nausea and vomiting
  
  BULLET::::- Sharp chest pain that gets worse with deep breathing or coughing
  
  BULLET::::- Shortness of breath
  
  BULLET::::- Decreased blood pressure and fast heart rate
  
  Section::::Types.
   Respiratory alkalosis
  
  Respiratory alkalosis is a medical condition in which increased respiration elevates the blood pH beyond the normal range (7.35–7.45) with a concurrent reduction in arterial levels of carbon dioxide. This condition is one of the four basic categories of disruption of acid–base homeostasis.
  
  Section::::Signs and symptoms.
  
  Signs and symptoms of respiratory alkalosis are as follows:
  
  BULLET::::- Palpitation
  
  BULLET::::- Tetany
  
  BULLET::::- Convulsion
  
  BULLET::::- Sweating
  
  Section::::Causes.
  
  Respiratory alkalosis may be produced as a result of the following causes:
  
  Section::::Mechanism.
   Important for good mucociliary clearance are the number of cilia, their structure, activity, and coordinated movement. Optimum functionality of mucociliary clearance presupposes a temperature of   and an absolute humidity of 44 mg/dm³ corresponding to a relative humidity of 100%. Under the condition of insufficient temperature and humidity, after a short time the ciliary cells suspend their transport function. Under such circumstances, bacterial germinal colonization is facilitated. Pulmonary infections and damaging of the pulmonic tissues may be the consequence.
  
  Section::::Function.:Mechanical ventilation.
   Symptoms of chemical (hydrocarbon) pneumonia may include:
  
  BULLET::::- burning of the nose, eyes, lips, mouth, and throat
  
  BULLET::::- dry cough
  
  BULLET::::- wet cough producing clear, yellow, or green mucus
  
  BULLET::::- cough producing blood or frothy pink matter
  
  BULLET::::- nausea or abdominal pain
  
  BULLET::::- chest pain
  
  BULLET::::- shortness of breath
  
  BULLET::::- painful breathing or pleuritis (an inflammation of the outside covering of the lungs)
  
  BULLET::::- headache
  
  BULLET::::- flu symptoms
  
  Section::::Treatment.
   Pneumonia
  
  Pneumonia is an inflammatory condition of the lung affecting primarily the small air sacs known as alveoli. Typically symptoms include some combination of productive or dry cough, chest pain, fever, and trouble breathing. Severity is variable.
  