Query: In the sugarcane region of El Salvador, as much as one-fifth of the population has chronic kidney disease, including over a quarter of the men, the presumed result of dehydration from working the fields they were able to comfortably harvest as recently as two decades ago.

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Mesoamerican nephropathy <=SEP=> Mesoamerican nephropathy ( MeN ) is a currently unexplained epidemic of chronic kidney disease of unknown origin ( CKDu ) , prevalent in the Pacific ocean coastal low lands of the mesoamerican region , including southern Mexico , Guatemala , El Salvador , Nicaragua , Honduras and Costa Rica . In rural areas of Nicaragua the disease is colloquially called creatinina .   This CKD epidemic in Central America spans along a nearly 1000 kilometer stretch of the Pacific coast . In El Salvador and Nicaragua alone , the reported number of men dying from this painful disease has risen five-fold in the last 20 years , although some researchers believe hidden cases have always been there and this increment in official data could be partially due to the recent increase in reports and improved case search , pushed by the growing social and political interest in the disease . In El Salvador , the disease has become the second leading cause of death among adult men , and according to a recent editorial , it has been estimated that this largely unknown epidemic has caused the premature death of at least 20,000 men in the region . Science Magazine reports : `` In El Salvador alone , PAHO 's latest figures say CKD of all causes kills at least 2,500 people in the country each year '' .   The people affected by the epidemic are mainly young and middle-aged male laborers in the agricultural sector , particularly sugarcane workers . The disease has also been found to be prevalent in other occupations with a high risk of heat stress , implying strenuous work ( miners , construction , port and transportation workers ) in the high temperatures of the coastlands . The epidemic appears to affect particular Pacific coastal regions of Nicaragua , El Salvador , Costa Rica , and Guatemala .

El Salvador <=SEP=> El Salvador ( -LSB- ɛl_ˈsælvədɔr -RSB- -LSB- el salβaˈðor -RSB- ) , officially the Republic of El Salvador ( -LSB- República de El Salvador , links = no -RSB- , literally `` Republic of The Savior '' ) , is the smallest and the most densely populated country in Central America . El Salvador 's capital and largest city is San Salvador . , the country had a population of approximately 6.38 million , consisting largely of Mestizos of European and Indigenous American descent .   El Salvador was for centuries inhabited by several Mesoamerican nations , especially the Cuzcatlecs , as well as the Lenca and Maya . In the early 16th century , the Spanish Empire conquered the territory , incorporating it into the Viceroyalty of New Spain ruled from Mexico City . In 1821 , the country achieved independence from Spain as part of the First Mexican Empire , only to further secede as part of the Federal Republic of Central America in 1823 . Upon the republic 's dissolution in 1841 , El Salvador became sovereign until forming a short-lived union with Honduras and Nicaragua called the Greater Republic of Central America , which lasted from 1895 to 1898 .   From the late 19th to the mid-20th century , El Salvador endured chronic political and economic instability characterized by coups , revolts , and a succession of authoritarian rulers . Persistent socioeconomic inequality and civil unrest culminated in the devastating Salvadoran Civil War ( 1979 -- 1992 ) , which was fought between the military-led government and a coalition of left-wing guerrilla groups . The conflict ended with a negotiated settlement that established a multiparty constitutional republic , which remains in place to this day .   El Salvador 's economy was historically dominated by agriculture , beginning with the indigo plant ( añil '' in Spanish ) , the most important crop during the colonial period , and followed thereafter by coffee , which by the early 20th century accounted for 90 percent of export earnings . El Salvador has since reduced its dependence on coffee and embarked on diversifying the economy by opening up trade and financial links and expanding the manufacturing sector . The colón , the official currency of El Salvador since 1892 , was replaced by the U.S. dollar in 2001 .   , El Salvador ranks 12th among Latin American countries in terms of the Human Development Index and fourth in Central America ( behind Panama , Costa Rica , and Belize ) due in part to ongoing rapid industrialisation . However , the country continues to struggle with high rates of poverty , inequality , and crime .

Kidney <=SEP=> The kidneys are two bean-shaped organs found on the left and right sides of the body in vertebrates . They filter the blood in order to make urine , to release and retain water , and to remove waste and nitrogen ( the excretory system ) . They also control the ion concentrations and acid-base balance of the blood . Each kidney feeds urine into the bladder by means of a tube known as the ureter . In humans , they are roughly 11 cm in length .   The kidneys regulate the balance of ions known as electrolytes in the blood , along with maintaining acid base homeostasis . They also move waste products out of the blood and into the urine , such as nitrogen-containing urea and ammonium . Kidneys also regulate fluid balance and blood pressure . They are also responsible for the reabsorption of water , glucose , and amino acids . The kidneys also produce hormones including calcitriol and erythropoietin . The kidneys also make an important enzyme , renin , which affects blood pressure through negative feedback .   Located at the rear of the abdominal cavity in the retroperitoneal space , the kidneys receive blood from the paired renal arteries , and drain into the paired renal veins .   Renal physiology is the study of kidney function , while nephrology is the medical specialty concerned with kidney diseases . Diseases of the kidney are diverse , but individuals with kidney disease frequently display characteristic clinical features . Common clinical conditions involving the kidney include the nephritic and nephrotic syndromes , renal cysts , acute kidney injury , chronic kidney disease , urinary tract infection , kidney stones , and urinary tract obstruction . Various cancers of the kidney exist . The most common adult renal cancer is renal cell carcinoma . Cancers , cysts , and some other renal conditions can be managed with removal of the kidney . This is known as nephrectomy . When renal function , measured by the glomerular filtration rate , is persistently poor , dialysis and kidney transplantation may be treatment options . Although they are not normally harmful , kidney stones can be extremely painful .

Hypertension <=SEP=> Hypertension ( HTN or HT ) , also known as high blood pressure ( HBP ) , is a long term medical condition in which the blood pressure in the arteries is persistently elevated . High blood pressure usually does not cause symptoms . Long term high blood pressure , however , is a major risk factor for coronary artery disease , stroke , heart failure , peripheral vascular disease , vision loss , and chronic kidney disease .   High blood pressure is classified as either primary ( essential ) high blood pressure or secondary high blood pressure . About 90 -- 95 % of cases are primary , defined as high blood pressure due to nonspecific lifestyle and genetic factors . Lifestyle factors that increase the risk include excess salt , excess body weight , smoking , and alcohol . The remaining 5 -- 10 % of cases are categorized as secondary high blood pressure , defined as high blood pressure due to an identifiable cause , such as chronic kidney disease , narrowing of the kidney arteries , an endocrine disorder , or the use of birth control pills .   Blood pressure is expressed by two measurements , the systolic and diastolic pressures , which are the maximum and minimum pressures , respectively . Normal blood pressure at rest is within the range of 100 -- 140 millimeters mercury ( mmHg ) systolic and 60 -- 90 mmHg diastolic . High blood pressure is present if the resting blood pressure is persistently at or above 140/90 mmHg for most adults . Different numbers apply to children . Ambulatory blood pressure monitoring over a 24-hour period appears more accurate than office best blood pressure measurement .   Lifestyle changes and medications can lower blood pressure and decrease the risk of health complications . Lifestyle changes include weight loss , decreased salt intake , physical exercise , and a healthy diet . If lifestyle changes are not sufficient then blood pressure medications are used . Up to three medications can control blood pressure in 90 % of people . The treatment of moderately high arterial blood pressure ( defined as > 160/100 mmHg ) with medications is associated with an improved life expectancy . The effect of treatment of blood pressure between 140/90 mmHg and 160/100 mmHg is less clear , with some reviews finding benefit and others finding a lack of evidence for benefit . High blood pressure affects between 16 and 37 % of the population globally . In 2010 hypertension was believed to have been a factor in 18 % of all deaths ( 9.4 million globally ) .