<unk>  is a type of vitamin B12 deficiency<unk> , a disease in which not enough red blood cells are produced due to the malabsorption of vitamin B12. Malabsorption in<unk>  results from the lack or loss of intrinsic factor needed for the absorption of vitamin B12.<unk>  is defined as a condition in which the blood has a lower than normal levels of red blood cells or hemoglobin concentration. The most common initial symptoms are tiredness, and weakness. Other signs and symptoms of<unk>  may include breathlessness, dizziness, a sore red tongue, lightheadedness, headaches, exercise intolerance, cold hands and feet,<unk> le or yellow skin, chest<unk> in, low blood pressure, and an irregular heartbeat. The digestive tract may also be disturbed giving symptoms that can include nausea and vomiting, heartburn, and loss of appetite. Weakened bones can also result leading to hip fractures. In severe cases of vitamin B12 deficiency, It may present with more severe symptoms, such as pins and needles sensations, memory problems, blurred vision, unsteady walking, poor balance, muscle weakness, impaired sense of taste and smell, poor reflexes, clumsiness, depression, confusion, guilt and psychosis. Without treatment, some of these problems may become permanent.<unk>  occurs due to an autoimmune response that produces antibodies that attack the<unk> rietal cells in the stomach lining and prevents them from creating intrinsic factor. Malabsorption may also result from the surgical removal of all or<unk> rt of the stomach or small intestine; from an inherited disorder or from cerain drugs or illnesses that damage the stomach lining. Other causes of low vitamin B12 include not enough dietary intake (which can be a risk in a vegan diet), celiac disease, or tapeworm infection. When suspected, diagnosis is made by blood tests initially a complete blood count, and occasionally, bone marrow tests. Blood tests may show fewer but larger red blood cells, low numbers of young red blood cells, low levels of vitamin B12, and antibodies to intrinsic factor.<unk>  can be treated with intramuscular injections or pills of vitamin B12. Nasal sprays and gels are also available for those who have trouble swallowing pills. Treatment may need to be lifelong.<unk>  due to autoimmune problems occurs in about one per 1000 people in the USA. Among those over the age of 60, about 2% have the condition. It more commonly affects people of northern European descent. Women are more commonly affected than men. With proper treatment, most people live normal lives. Due to a higher risk of stomach cancer, those with<unk>  should be checked regularly for this. The first clear description was by Thomas Addison in 1849. The term<unk> " means "deadly", and this term came into use because before the availability of treatment the disease was often fatal.
Pernicious anemia
Zinc deficiency
Iron poisoning
Zinc toxicity
Hookworm infection
Fruit allergy
Pinworm infection
African iron overload