dizziness

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. 

difficulty walking, headache, poor coordination, vision problems

Head injury is a trauma to the head, that may or may not include injury to the brain (see also brain injury). ... 

breathing fast, chest pain, difficulty breathing, dizziness

In medicine, hyperventilation (or overbreathing) is the state of breathing faster and/or deeper than necessary, thereby reducing the carbon dioxide concentration of the blood below normal. ... 

chest pain, difficulty breathing, passing out, weakness

Somatization disorder (also Briquet's disorder or, in antiquity, hysteria) is a psychiatric diagnosis applied to patients who chronicly and persistently complain of varied physical symptoms that have no identifiable physical origin. One common general etiological explanation is that internal psychological conflicts are unconsciously expressed as physical signs. ... 

headache, nausea, vision problems, vomiting

Migraine is a painful neurological condition, of which the most common symptom is an intense and disabling episodic headache. Migraine headaches are usually characterized by severe pain on one or both sides of the head. Absent serious head injuries, stroke, and tumors, the recurring severity of the pain indicates a vascular headache rather than a tension headache. Migraines are often accompanied by photophobia (hypersensitivity to light), phonophobia (hypersensitivity to sound) and nausea. ... 

headache, irritability, pain in neck, tight feeling on back of neck

Tension headaches, which were renamed tension-type headaches by the International Headache Society in 1988, are the most common type of primary headaches. The pain can radiate from the neck, back, eyes, or other muscle groups in the body. Tension-type headaches account for nearly 90% of all headaches. Approximately 3% of population suffers from chronic-tension type headache. ... 

poor appetite, stomach pain, vomiting, weakness

dizziness, passing out, vomiting, weakness

Dehydration (hypohydration) is the removal of water (hydro in ancient Greek) from an object. Medically, condition in which the body contains an insufficient volume of water for normal functioning. ... 

headache, increased sweating, passing out, weakness

Hypoglycemia (hypoglycæmia in the UK) is a medical term referring to a pathologic state produced by a lower than normal amount of sugar (glucose) in the blood. The term hypoglycemia literally means "under-sweet blood" (Gr.hypo-, glykys, haima). Hypoglycemia can produce a variety of symptoms and effects but the principal problems arise from an inadequate supply of glucose as fuel to the brain, resulting in impairment of function (neuroglycopenia). Derangements of function can range from vaguely "feeling bad" to coma, and (rarely) permanent brain damage or death. Hypoglycemia can arise from many causes and can occur at any age. The most common forms of moderate and severe hypoglycemia occur as a complication of treatment of diabetes mellitus with insulin or oral medications. Hypoglycemia is usually treated by the ingestion or administration of glucose, or foods digestible to glucose. ... 

dizziness, headache, vision problems, vomiting