Basics Decreased Appetite and Unexplained Weight Loss in Men By Jerry Kennard, PhD Jerry Kennard, PhD, is a psychologist and associate fellow of the British Psychological Society. Learn about our editorial process Jerry Kennard, PhD Fact checked by Fact checked by Adah Chung on August 10, 2020 linkedin Adah Chung is a fact checker, writer, researcher, and occupational therapist. Learn about our editorial process Adah Chung Updated on September 17, 2020 Print Nico De Pasquale Photography / Getty Images A decrease in appetite is quite common during illness, such as when suffering from a bout of influenza or other relatively short-term illnesses. Nausea is also associated with decreased appetite. Appetite can also decrease in times of emotional upset, depression, boredom or anxiety. Generally, when the illness or emotional problem is resolved, the appetite returns to normal. If a decreased appetite is persistent, is accompanied by other symptoms such as those listed below, or there is unexplained weight loss, medical attention should be sought. Infections That Can Cause Decreased Appetite Infection can lead to a decrease in appetite. Infections that are often associated with a loss of appetite include: Respiratory infections that affect the lungsPneumoniaInfluenzaKidney infection, such as pyelonephritisHepatitis and conditions that cause liver inflammationHIV/AIDS Other Causes Factors that can affect appetite are many and can vary greatly. Other causes can include: Psychological issues such as stress, anxiety, depression, grief or eating disorders like anorexiaStimulants, weight loss medications, and medications for attention deficit and hyperactivity disorder (ADHD) like amphetamines (e.g., Adderall)Illicit drugs like hallucinogenics, inhalants, and LSDMigraine headachesHypercalcemia, a condition in which there is too much calcium in the bloodHypokalemia, a condition where there is too little potassium in the bloodHigh alcohol intakeCongestive heart failureCancer and treatments like chemotherapyAcid refluxFood allergiesFood poisoningAcute painIntestinal blockageGastrointestinal ulcersAppendicitisDigestive disorders such as irritable bowel syndrome (IBS), Crohn's disease, celiac disease and colitis When to Seek Help If a loss of appetite is accompanied by chest pains, shortness of breath, sweating, blurred vision or confusion—the warning signs of a heart attack or stroke—seek medical attention immediately. Also, seek medical attention if any of the following signs and symptoms accompany decreased appetite: Unable to eat or drink for more than 12 hoursA high fever above 103 degrees Fahrenheit (40 degrees Celsius)A severe headacheExtreme abdominal painStiffness in the neckDehydration with symptoms including dizziness, increased thirst, and low urine output Weight Loss From Decreased Appetite During periods of decreased appetite, weight loss can obviously occur, but there are occasions when weight loss is unexplained and may be unrelated to decreased appetite. When drastic weight loss reaches more than 10% of the starting weight over a short period of time (for example, 3 months), a search for medical causes should be undertaken, and medical attention is required. Typically, dramatic weight loss is due to an inability to digest and absorb food properly, or the intake of calories is insufficient and outstripped by the energy needs of the body. Weight Loss From Malabsorption Malabsorption is the term used to describe the inability of the body to absorb enough nutrients from the consumption of food and drink. This can lead to malnutrition and unexplained weight loss. The most common nutrients that are not sufficiently absorbed are fats (lipids); however, malabsorption can apply to nutrients like carbohydrates, proteins, minerals like iron and calcium, vitamins, and electrolytes like potassium and sodium. Malabsorption can be caused by several factors, including: Digestive enzyme problemsGallbladder problemsSmall intestine problemsParasitic infectionsSome medications causing long-term diarrheaHyperthyroidism creating an excessive energy demandFeverCancerDrug abuse Was this page helpful? Thanks for your feedback! Looking to lose weight? Our nutrition guide can help you get on the right track. Sign up for our newsletter and get it free! Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Simmons WK, Burrows K, Avery JA, et al. Depression-Related Increases and Decreases in Appetite: Dissociable Patterns of Aberrant Activity in Reward and Interoceptive Neurocircuitry. Am J Psychiatry. 2016;173(4):418-428. doi:10.1176/appi.ajp.2015.15020162 Bosch X, Monclús E, Escoda O, et al. Unintentional weight loss: Clinical characteristics and outcomes in a prospective cohort of 2677 patients. PLoS One. 2017;12(4):e0175125. doi:10.1371/journal.pone.0175125 Ulrich-Lai YM, Fulton S, Wilson M, Petrovich G, Rinaman L. Stress Exposure, Food Intake and Emotional State. 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