weakness

fever, headache, nausea, weakness

Influenza, commonly known as the flu, is an infectious disease of birds and mammals caused by an RNA virus of the family Orthomyxoviridae (the influenza viruses). In humans, common symptoms of influenza infection are fever, nausea, vomiting, sore throat, muscle pains, severe headache, coughing, and weakness and fatigue. In more serious cases, influenza causespneumonia, which can be fatal, particularly in young children and the elderly. Sometimes confused with the common cold, influenza is a much more severe disease and is caused by a different type of virus. Similarly, the unrelated gastroenteritis is sometimes called "stomach flu" or "24-hour flu". 

dizziness, paleness, palpitations, weakness

Anemia (AmE) or anaemia (BrE), from the Greek meaning "without blood", refers to a deficiency of red blood cells (RBCs) and/or hemoglobin. This results in a reduced ability of blood to transfer oxygen to the tissues, causing hypoxia; since all human cells depend on oxygen for survival, varying degrees of anemia can have a wide range of clinical consequences. Hemoglobin (the oxygen-carrying protein in the red blood cells) has to be present to ensure adequate oxygenation of all body tissues and organs. 

left upper quadrant abdominal pain, stomach pain, upper abdominal pain, vomiting

Gastroenteritis involves diarrhoea or vomiting, with noninflammatory infection of the upper small bowel, or inflammatory infection of the colon, both part of the gastrointestinal tract. ... 

poor appetite, stomach pain, vomiting, weakness

irregular menstrual periods, poor appetite, stomach pain, upper abdominal pain

Alcoholism is the consumption of or preoccupation with alcoholic beverages to the extent that this behavior interferes with the alcoholic's normal personal, family, social, or work life. Alcohol consumption caused by alcoholism can result in psychological and physiological conditions, and ultimately in death. Alcoholism is one of the world's most costly drug use problems; with the exception of nicotine addiction, alcoholism is more costly to most countries than all other drug use problems combined. ... 

difficulty breathing, increased sweating, palpitations, stomach pain

Anxiety is an unpleasant, emotional state of high energy that involves a complex combination of emotions that include fear, apprehension, and worry. It is often accompanied by physical sensations such as heart palpitations, nausea, chest pain, shortness of breath, or tension headache. ... 

breathing fast, chest pain, cough, difficulty breathing

Asthma is a chronic disease of the respiratory system in which the airway occasionally constricts, becomes inflamed, and is lined with excessive amounts of mucus, often in response to one or more triggers. These acute episodes may be triggered by such things as exposure to an environmental stimulant (or allergen), cold air, exercise or exertion, or emotional stress. In children, the most common triggers are viral illnesses such as those that cause the common cold. This airway narrowing causes symptoms such as wheezing, shortness of breath, chest tightness, and coughing, which respond to bronchodilators. Between episodes, most patients feel fine. ... 

decreased sexual desire in males, difficulty sleeping, poor appetite, weakness

In everyday language depression refers to any downturn in mood, which may be relatively transitory and perhaps due to something trivial. This is differentiated from Clinical depression which is marked by symptoms that last two weeks or more and are so severe that they interfere with daily living. ... 

incontinence of urine in females, increased thirst, urinating often, weight gain

Diabetes mellitus type 2 (formerly called diabetes mellitus type II, non-insulin-dependent diabetes (NIDDM), obesity related diabetes, or adult-onset diabetes) is a metabolic disorder that is primarily characterized by insulin resistance, relative insulin deficiency, and hyperglycemia. It is presently incurable. It is rapidly increasing in the developed world, and there is some evidence that this pattern will be followed in much of the rest of the world in coming years. The CDC has characterized the increase as an epidemic. ... 

anemia, irregular menstrual periods, paleness, vaginal bleeding unrelated to periods

Dysfunctional Uterine Bleeding (DUB) is the most common cause of functional abnormal uterine bleeding, which is abnormal genital tract bleeding based in the uterus and found in the absence of demonstrable organic pathology. Diagnosis must be made by exclusion, since organic pathology must first be ruled out. It can be classified as ovulatory or anovulatory, depending on whether ovulation is occurring or not. ...