Malabsorption may also result from the surgical removal of all or part of the stomach or small intestine; from an inherited disorder or from certain 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.Pernicious anemia 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.Pernicious anemia 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 pernicious anemia should be checked regularly for this. The first clear description was by Thomas Addison in 1849. The term "pernicious" means "deadly", and this term came into use because before the availability of treatment the disease was often fatal. Signs and symptoms
Pernicious anemia often presents slowly, and can cause harm insidiously and unnoticeably.
Pernicious anemia is a type of vitamin B12 deficiency anemia, a disease in which not enough red blood cells are produced due to the malabsorption of vitamin B12. Malabsorption in pernicious anemia results from the lack or loss of intrinsic factor needed for the absorption of vitamin B12. Anemia is defined as a condition in which the blood has a lower than normal amount of red blood cells or hemoglobin. The disease may come on slowly and insidiously.The most common initial symptoms are tiredness, and weakness. Other signs and symptoms of anemia include breathlessness, dizziness, a sore red tongue, lightheadedness, headaches, poor ability to exercise, cold hands and feet, low blood pressure, pale or yellow skin, chest pain, and an irregular heartbeat. The digestive tract may also be disturbed giving symptoms that can include nausea and vomiting, heartburn, upset stomach and loss of appetite. Pernicious anemia can cause osteoporosis and may lead to bone fractures. Symptoms of severe vitamin B12 deficiency can include tingling or numbness in the hands and feet, memory problems, blurred vision, unsteady walking, poor balance, muscle weakness, impaired sense of taste and smell, poor reflexes, clumsiness, depression, and confusion. Without treatment, some of these problems may become permanent.Pernicious anemia occurs due to an autoimmune response that produces antibodies that attack the parietal cells in the stomach lining and prevents them from creating intrinsic factor.