Pressure system minima in the pressure field. The minima are called low-pressure areas, and the maxima are called high-pressure areas. A "High" is often shown as H, and a "low" is shown as L. Elongated areas of low pressure, or troughs, are sometimes plotted as thick, brown dashed lines down the trough axis. Isobars are commonly used to place surface boundaries from the horse latitudes poleward, while streamline analyses are used in the tropics. A streamline analysis is a series of arrows oriented parallel to wind, showing wind motion within a certain geographic area. Cs depict cyclonic flow or likely areas of
Blood pressure 8 mmHg in the left atrium. Variants of venous pressure include: Normally, the pressure in the pulmonary artery is about 15 mmHg at rest. Increased blood pressure in the capillaries of the lung causes pulmonary hypertension, leading to interstitial edema if the pressure increases to above 20 mmHg, and to pulmonary edema at pressures above 25 mmHg. Disorders of blood pressure control include high blood pressure, low blood pressure, and blood pressure that shows excessive or maladaptive fluctuation. Arterial hypertension can be an indicator of other problems and may have long-term adverse effects. Sometimes it can be an acute problem,