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FACT SHEET: Anemia (includes iron deficiency anemia; aplastic anemia [also known as ‘hypoplastic anemia’; includes Fanconi’s anemia]; vitamin B12 deficiency anemia [which includes pernicious anemia]; folate deficiency anemia; hemolytic anemia [which includes sickle cell anemia, thalassemia, malarial anemia, and G6PD-deficiency anemia]; anemia of chronic disease; anemia related to kidney disease; and anemia related to pregnancy)

Date of Publication: March 5, 2019

Note: Sickle cell anemia, thalassemia, and glucose-6-phosphate dehydrogenase (G6PD) deficiency — as well as the therapeutic modalities of chemotherapy, radiation therapy, and hematopoietic stem cell transplantation (which includes bone marrow and blood stem cell transplantation) for aplastic anemia — are addressed in detail in separate fact sheets.

Is the initiation of non-invasive dental hygiene procedures* contra-indicated?

  • No.

Is medical consult advised?  

  • Yes, if previously undiagnosed or inadequately treated anemia is suspected. For instance, early diagnosis and treatment is important to prevent potentially irreversible neurologic signs in vitamin B12 and folate deficiency anemias. Similarly, aplastic anemia can be life-threatening, and prompt diagnosis and treatment are critical.
  • Yes, if patient/client has sickle cell anemia, thalassemia, or aplastic anemia in which case liaison with the patient/client’s hematologist (blood specialist) or experienced internist, paediatrician, or family physician is advisable regarding the severity and management of the patient’s disorder before undertaking dental hygiene treatment for the first time.

Is the initiation of invasive dental hygiene procedures contra-indicated?**

  • Yes, all types of anemia are blood disorders, and clearance is required from a physician or dentist, or both (as per Ontario Regulation 510/07 pursuant to the Dental Hygiene Act, 1991). In particular, sickle cell anemia, thalassemia, and aplastic anemia are blood disorders that may often affect appropriateness or safety. Other possible contra-indications germane to several types of anemia include active chemotherapy and/or radiation therapy, as well as significant immunosuppression and/or bleeding disorder (e.g., thrombocytopenia) resulting from the disease itself (e.g., aplastic anemia) and/or its treatment.

Is medical consult advised? 

  • See above. Patients/clients with sickle cell anemia may be in danger of a sickle crisis if the disease is not detected and managed before invasive procedures are started. Patients/clients with sickle cell disease, thalassemia, and aplastic anemia should undergo a determination of the most appropriate setting for provision of invasive dental hygiene care (i.e., whether in the setting of primary or secondary [hospital-based] care). 

Is medical clearance required? 

  • Yes, if anemia has been diagnosed or is suspected. (Note: Most patients/clients presenting with mild anemia [such as mild iron deficiency anemia] are likely to be medically cleared for dental hygiene procedures, because minor blood loss during procedures is likely to be well tolerated. However, clearance/consultation [including ascertainment of the specific type of anemia] is important for understanding: the implications of the patient/client’s anemia for procedures; complications, co-morbidities, and/or severity of the patient/client’s anemia; and any requirements for antibiotic prophylaxis.) 
  • Medical clearance may also be required if patient/client is being treated with medications or treatment modalities associated with immunosuppression +/- increased risk of infection (e.g., corticosteroids in the management of sickle cell disease; immunosuppressive medications in management of aplastic anemia; etc.); or chemotherapy and/or radiation therapy [as a prelude to hematopoietic stem cell transplantation] in the management of sickle cell disease or aplastic anemia).
  • Yes, if thrombocytopenia exists or is suspected (particularly applicable to aplastic anemia).

Is antibiotic prophylaxis required?  

  • Possibly, if there is compromised immunity (e.g., in sickle cell disease, thalassemia, or aplastic anemia) which places patient/client at risk for distant-site infection from transient bacteremia resulting from invasive procedures. As well, antibiotic prophylaxis is often recommended in sickle cell disease for major dental surgical procedures to reduce risks of wound infections and osteomyelitis (even though the evidence supporting such use is largely lacking).
  • Possibly, for some patients/clients undergoing chemotherapy and/or radiotherapy1.
  • Possibly, for some patients/clients with aplastic anemia being treated with immunosuppressive medications (e.g., anti-thymocyte globulin and/or cyclosporine).

Is postponing treatment advised?

  • Yes, pending medical clearance (and potential treatment) for all anemias.
  • Yes, if anemia is suspected to be severe and the patient/client has attendant signs/symptoms. Patients/clients who are short of breath and in whom hemoglobin (Hb) levels are < 110 g/L [also expressed as 11.0 g/dL], have an abnormal heart rate, or have an oxygen saturation < 91% (as determined by pulse oximetry) are considered medically unstable, and routine dental/dental hygiene treatment should be deferred until health status improves.
  • Possibly, depending on blood indices (which indicate degree of anemia and/or immunosuppression and/or thrombocytopenia) in patients/clients undergoing chemotherapy or radiotherapy. Elective invasive procedures should be deferred until after chemo- or radiation-induced immunosuppression ceases.
  • In the case of hematopoietic stem cell transplantation, elective oral procedures, including scaling and polishing, should be delayed until the patient/client’s immune system returns to normal; typically, this takes 6 to 12 months post-transplantation.

Oral management implications

  • Sickle cell disease, thalassemia, chemotherapy, radiotherapy, and hematopoietic stem cell transplantation each have numerous oral management implications, which are described in their respective CDHO fact sheets.
  • The dental hygienist may be the first healthcare professional to observe some of the signs/symptoms associated with certain anemias (e.g., oral manifestations of vitamin B12 or folate deficiency2), and thus she/he plays an important role in timely medical referral.
  • The dental hygienist should ask the patient/client about the type, severity, and treatment of the patient/client’s anemia to inform the oral management plan. 
  • Depending on the type of the patient/client’s anemia, the dental hygienist may play an important role in discussing the importance of an appropriate diet in the maintenance of oral health. Dietitian referral may also be appropriate.

Oral manifestations

  • Common to most types of anemia are mucosal and skin pallor, angular cheilitis, erythema and atrophy of the oral mucosa, and loss of filiform and fungiform papillae on the dorsum of the tongue. Foliate and circumvallate papillae are not usually affected.
  • Iron deficiency can manifest as burning sensation of the oral mucosa and tongue, atrophic glossitis, swelling of the tongue, lingual varicosity, lichen planus, and xerostomia.3 Oral candidiasis has also been linked to iron deficiency anemia, which exacerbates angular cheilitis and depapillation of the tongue.
  • Aplastic anemia causes manifestations related to the generalized decrease in red and white blood cells as well as platelets. Thus, infection (e.g., candidiasis), spontaneous gingival bleeding, petechiae, and purpuric spots may occur intra- and peri-orally. Diffuse gingival hyperplasia and necrotizing gingivostomatitis may also occur.
  • Vitamin B12 and folate deficiencies can manifest as glossitis, glossodynia, smooth tongue (i.e., depapillation of filiform papillae), thickened tongue, lingual paresthesia/burning sensation, dysgeusia, oral candidiasis, stomatitis, recurrent oral ulcers, diffuse erythematous mucositis and pruritis.4
  • Hemolytic anemia can manifest with oral evidence of jaundice.5 Furthermore, dental radiographs may show enlarged, irregular bone medullary spaces associated with bone marrow hyperplasia (due to erythrocyte production response to red blood cell destruction); increased widening and decreased numbers of trabeculations (particularly in alveolar bone); loss of height of alveolar bone; and osteoporosis (particularly thinning of the inferior border of the mandible). Bone appears more radio-translucent with prominent striations, and the trabeculae between teeth may take on a coarse horizontal row or “staircase” pattern.
  • Mucositis may be present in patients/clients undergoing chemotherapy or radiation therapy related to bone marrow transplantation (e.g., for sickle cell disease or aplastic anemia).

Related signs and symptoms

  • Anemia is a condition in which the red blood cell count or the hemoglobin level is below normal6. For women, anemia is typically defined as hemoglobin level < 120 g/L (also expressed as 12.0 g/dL), and in men a typical definition is < 130 g/L (also expressed as 13.0 g/dL)7 . The ability of the blood to carry oxygen or give up oxygen to other cells is decreased in anemic patients/clients.
  • Anemia has three main causes: blood loss; decreased production of red blood cells (RBCs) or hemoglobin; and increased destruction of red blood cells8. Anemia is a sign of an underlying disease process, and it is usually classified as either acute or chronic. About 3% of Canadians have anemia. 
  • Depending on the size of the red blood cells, anemia may be characterized as normocytic (normal size), microcytic (small), or macrocytic (large)9. Depending on the colour (i.e., hemoglobin content) of the red blood cells, anemia may be characterized as normochromic (normal colour, because the concentration of hemoglobin in individual red blood cells is within the standard range), hypochromic (paler than normal, due to reduced hemoglobin content in individual red blood cells), or hyperchromic (darker than normal, due to increased hemoglobin content in individual red blood cells).
  • While some patients/clients with mild anemia have no overt signs/symptoms, more severe anemia can result in:
    • fatigue;
    • weakness;
    • pallor (pale appearance) or jaundice (yellow skin and eyes);
    • shortness of breath (particularly upon exertion);
    • tachycardia (elevated heart rate and hence pulse);
    • palpitations and irregular heart rhythm;
    • low blood pressure;
    • worsening heart problems (e.g., angina, myocardial infarction, enlargement of the heart, or heart failure); 
    • hair loss;
    • malaise;
    • lightheadedness or dizziness; and
    • loss of consciousness.
  • If the anemia is chronic, the patient/client’s body may adjust to low oxygen levels in the blood, and the individual may not have pronounced symptomatology unless the anemia becomes severe. In contrast, if the anemia occurs acutely (i.e., rapidly), the patient/client may experience severe signs/symptoms relatively quickly, even with relatively mild lowering of hemoglobin level.
  • Iron deficiency anemia (IDA) is the most common anemia in Canada and worldwide, is characterized by microcytosis and hypochromia, and is often asymptomatic. Low grade IDA is relatively common in pre-menopausal women due to loss of blood monthly through menstruation, particularly if periods are heavy. This form of anemia can also be caused by ongoing bleeding associated with colorectal cancer, stomach ulcers (which can be aspirin- and NSAID10-induced), and inflammatory bowel disease (i.e., Crohn’s disease or ulcerative colitis). In addition to signs/symptoms common to all forms of anemia, manifestations of more severe iron deficiency include brittle nails and hair, koilonychia (spoon-shaped nails), pica (unusual cravings for non-food items, such as ice, dirt, or paint), and restless legs syndrome. In young children, iron deficiency is most commonly due to a diet lacking in iron.
  • Aplastic anemia is a life-threatening condition caused by failure of the bone marrow to produce adequate numbers of red blood cells (and white blood cells and platelets).11 Onset can be gradual or sudden. In addition to signs/symptoms common to all forms of anemia, other sequelae can be recurrent infections (due to immunocompromised state resulting from low white blood cell count) and abnormal bleeding and bruising (due to low platelet count). Retinal and cerebral hemorrhages may occur.
  • Vitamin B1212 deficiency anemia is a macrocytic13 anemia caused by either inadequate intake of dietary vitamin B12 (e.g., in long-standing strict veganism or vegetarianism14 without vitamin supplementation) or by malabsorption/poor processing of vitamin B12.15 In addition to signs/symptoms common to all forms of anemia, other manifestations associated with this macrocytic anemia can be neurologic (e.g., numbness and tingling in hands and feet; muscle weakness; loss of reflexes; loss of balance; difficulty walking; confusion; and dementia) and gastrointestinal (e.g., nausea, vomiting, diarrhea, constipation, abdominal bloating, decreased appetite, and liver enlargement).  
  • Folate16 deficiency17 can cause macrocytic anemia, with clinical signs/symptoms similar to those of vitamin B12 deficiency. Women who are folate deficient during pregnancy are at risk of bearing offspring with neural tube defects (e.g., spina bifida). 
  • Hemolytic anemia occurs when RBCs are destroyed faster than the bone marrow can replace them.18 In addition to signs/symptoms common to all forms of anemia, other signs may include dark urine, jaundice, and enlargement of the spleen.
  • Anemia of chronic disease may occur in patients/clients with longstanding chronic diseases that interfere with the production of RBCs (e.g., cancer, HIV/AIDS, rheumatoid arthritis, Crohn’s disease, and other chronic inflammatory or autoimmune diseases).
  • Anemia related to kidney disease occurs in patients/clients with chronic kidney disease (CKD) or end stage renal disease (ESRD). These conditions result in a reduction in erythropoietin stimulating hormone, which is necessary to stimulate normal RBC production by the bone marrow.
  • Anemia related to pregnancy occurs because fluid gain during pregnancy dilutes the blood, thereby lowering the relative concentration of red blood cells. As well, there is increased demand for additional iron to support the growth of the fetus, and thus iron deficiency may also occur in up to 20% of pregnancies.
  • Anemia caused by bleeding may present as black tarry stools; blood in urine or stool; or coughing up blood.
  • Other risk factors for, or causes of, anemia include lymphoma; myelodysplasia19; hypothyroidism; hyperthyroidism; alcoholism; micronutrient deficiencies such as deficiencies of vitamins A or C; the use of medications that can depress red blood cell production (e.g., androgen-deprivation therapy [ADT] for the treatment of prostate cancer); and advanced age (with person over age 65 years being at increased risk).
  • Prognosis depends on the underlying cause of anemia, its severity, and the overall health status of the patient/client. Many forms of anemia are curable or at least treatable. Some inherited anemias — such as sickle cell anemia — can lead to life-threatening complications. Severe or long-lasting anemia can damage the heart, brain, and other organs. In children, prolonged anemia is associated with psychomotor and cognitive defects. The rapid loss of a lot of blood results in acute, severe anemia that can be fatal.

References and sources of more detailed information

Date: August 7, 2018
Revised: February 22, 2023


1 particularly total body irradiation for bone marrow/stem cell transplantation purposes (e.g., for treatment of aplastic anemia or sickle cell disease)
2 These oral changes may precede symptomatic anemia and macrocytosis, as well as many systemic indicators of vitamin deficiency.
3 Long-standing iron deficiency anemia can rarely be associated with (and perhaps be causal to) Plummer-Vinson syndrome (also known as Paterson-Brown-Kelly syndrome). This condition includes dysphagia, glossitis, angular cheilitis, atrophy of the papillae on the dorsum of the tongue, atrophy of the upper gastrointestinal tract, and a predisposition to esophageal and oral cancer.
4 Deficiency of vitamin B12 or folate impairs DNA synthesis, which results in abnormalities in the rapidly dividing epithelial cells of the mouth and gastrointestinal tract.
5 The jaundice is caused by hyperbilirubinemia due to excessive destruction of red blood cells.
6 Red blood cells are made in the bone marrow, and they normally live between 100 to 120 days. They contain the protein hemoglobin, which carries oxygen from the lungs to cells throughout the body, as well as carbon dioxide from the body’s cells to the lungs. Hemoglobin imparts the familiar red colour to RBCs.
7 Reference ranges differ slightly from one laboratory to another. Anemia is usually detected or confirmed via a complete blood count (CBC) laboratory test, which (in addition to white blood cell and platelet counts) provides information on the number of red blood cells (RBC count), total amount of hemoglobin in blood, and the fraction of blood comprised of RBCs (hematocrit). A hemoglobin rapid test is also now available, which is performed using a few drops of blood from a finger prick (rather than the venipuncture required for a CBC).
8 Investigation of anemia depends on the suspected cause(s), and treatment depends on the particular confirmed cause.
9 Anemia (low hemoglobin) is often classified according to mean corpuscular volume (MCV), which signifies the average volume of individual red blood cells. MCV < 80 fL is referred to as microcytic anemia (low cell volume, as in iron deficiency and thalassemia), MCV in the normal range (80 to 100 fL) is normocytic anemia (normal cell volume, as in anemia of chronic disease and anemia related to kidney disease), and MCV > 100 fL is macrocytic anemia (large cell volume, as in vitamin B12 or folate deficiency).
10 NSAID = nonsteroidal anti-inflammatory drug (e.g., ibuprofen, naproxen, and diclofenac)
11 Causes of aplastic anemia include certain primary cancers (e.g., leukemia and multiple myeloma) as well as metastases to bone marrow; cancer treatments (i.e., chemotherapy and radiation therapy); chronic exposure to toxic chemicals (e.g., benzene), certain viral infections (e.g., parvovirus B-19, HIV and Epstein Barr virus); certain medications (e.g., carbamazepine and phenytoin used in the treatment of epilepsy; chloramphenicol, an antibiotic used to treat certain infections); myelodysplastic syndromes; and genetic abnormalities (e.g., Fanconi’s anemia, which is the most common inherited anemia that leads to severe, progressive bone marrow failure). Patients/clients with Fanconi’s anemia often have other birth defects (e.g., low birth weight and failure to thrive; short stature; skeletal abnormalities of the spine and hip; anomalies of the thumb, hand, and arm; skin discolouration; small head and/or eyes; kidney problems; heart defects; digestive tract abnormalities; and intellectual disability); they are also at elevated risk of developing leukemia and other cancers, and many children do not survive to adulthood. 
12 Vitamin B12 is also known as cobalamin.
13 In addition to macrocytes (enlarged circulating erythrocytes), both vitamin B12 and folate deficiency anemias are also characterized by the presence of megaloblasts (enlarged RBC precursors).
14 Vitamin B12 is found only in bacteria and foods of animal origin.
15 Pernicious anemia is caused by malabsorption of vitamin B12 secondary to inadequate gastric production or defective functioning of intrinsic factor (a protein required for vitamin B12 absorption from the small intestine). Other causes of vitamin B12 deficiency include celiac disease, Crohn’s disease, gastric cancer, gastrectomy, bacterial overgrowth in the small intestine, long-term alcoholism, HIV/AIDS, and certain medications (e.g., neomycin, colchicine, and metformin). Malabsorption of vitamin B12 has also been associated with long-term use of H2-receptor antagonists (e.g., ranitidine) and proton-pump inhibitors (e.g., omeprazole), which are prescribed for gastroesophageal reflux disease (GERD).
16 Folate is a natural form of vitamin B9, whereas folic acid is a synthetic form of vitamin B9 used in vitamin supplements.
17 Folate deficiency can result from inadequate absorption from the gastrointestinal tract, inadequate intake (e.g., under-consumption of green, leafy vegetables), and long-term alcoholism. Folate, along with vitamin B12, is involved in making the heme molecule, which is essential for hemoglobin to function properly.
18 Hemolysis of red blood cells is involved in medication-induced hemolytic anemia, blood transfusion related hemolysis, autoimmune hemolytic anemia, and hemolytic disease of the newborn. Hemolytic anemia may be acquired (e.g., malarial anemia) or inherited (e.g., sickle cell anemia, thalassemia, or glucose-6-phosphate dehydrogenase [G6PD] deficiency). Malaria-induced anemia is unlikely to be encountered by a dental hygienist in Ontario. However, patients/clients who have lived or travelled in malaria-endemic countries (particularly if no preventive antimalarial medications were taken) could conceivably present with this parasite-induced anemia, whose symptomatology includes flu-like illness with high fever, chills, sweating, and gastrointestinal distress.
19 Myelodysplasia is similar to aplastic anemia in that the production of blood cells is decreased. However, in addition the blood cells do not function properly.

* Includes oral hygiene instruction, fitting a mouth guard, taking an impression, etc.
** Ontario Regulation 501/07 made under the Dental Hygiene Act, 1991. Invasive dental hygiene procedures are scaling teeth and root planing, including curetting surrounding tissue.