Complete blood count (CBC)

Pick Ordered or Not ordered to see the note.

Indicated when

• —Fatigue, pallor, unexplained bruising or bleeding, recurrent infections, or other symptoms that could reflect anemia, a white cell disorder, or a platelet problem, including as part of an initial work-up for persistent tiredness
• —Monitoring a known hematologic condition, or a medication known to affect blood counts (for example, certain immunosuppressants or chemotherapy)
• —Baseline assessment before starting a treatment that can affect blood counts

Not indicated when

• —Routine annual or 'wellness panel' screening in an asymptomatic adult with no symptoms, risk factors, or medication requiring blood count monitoring [5]

Why not

In a person with no symptoms or risk factors, a CBC can return a mildly abnormal value, for example a slightly low or high platelet or white cell count, that is not clinically significant but prompts repeat testing or further investigation, adding cost and anxiety without a clear benefit [5].

Better first step

Order a CBC when there is a specific symptom, risk factor, or monitoring need; for a patient presenting mainly with fatigue, a CBC alongside ferritin is a reasonable, low-cost first step rather than a routine annual test on its own.

Typical ND rationale

An ND may include a CBC in a wellness panel as a broad, inexpensive first look at red cells, white cells, and platelets, reasoning that it can flag anemia, infection, or a blood disorder before other symptoms become obvious.

Ontario coverage & CONO orderability

OHIP status

insured

Listed by name in the 2026 Schedule of Benefits for Laboratory Services (L393 Complete Blood Count, includes WBC differential, platelet count, RBC count, WBC count, hematocrit and hemoglobin, fee $3.98). Insured when ordered by a physician, midwife, or NP who has clinically assessed the patient; the same test ordered by a naturopathic doctor is not an insured service and is billed privately (Reg. 552 s.22(1); SOB-LS 2026 preamble).

CONO orderable

Yes — CONO list #43

CONO list item 43, blood: 'Complete Blood Count.'

Linked conditions

• tired ↗

Counselling script

“A CBC is a good first test when there's a specific reason, like fatigue, unusual bruising, or a medication that needs monitoring, so if that applies to you today, it makes sense to check it. Without a symptom or reason like that, I don't order a CBC as routine yearly screening, since a random abnormal result in someone who feels well usually just leads to more testing rather than helping. If anything like fatigue, bruising, or bleeding comes up later, let's check it then.”

Revisit if

• —New or worsening fatigue, pallor, bruising, or bleeding
• —Recurrent or unusual infections
• —Starting a medication known to affect blood counts

References

1. [1]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026). linkComplete Blood Count (L393) is listed by name in the 2026 OHIP Schedule of Benefits for Laboratory Services
2. [2]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026). linkCommunity lab tests are insured only when ordered under the Schedule by an authorized prescriber
3. [3]Government of Ontario (e-Laws) (2026). Health Insurance Act, R.R.O. 1990, Reg. 552: General, s. 22 (insured laboratory services). linkA lab test is insured only when ordered by a physician, midwife, or NP who has clinically assessed the patient
4. [4]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026). linkTests ordered by anyone other than an authorized provider, including NDs, are not insured services
5. [5]College of Family Physicians of Canada / Choosing Wisely Canada (2026). Family Medicine: Fifteen Tests and Treatments to Question. linkDon't do annual screening blood tests unless directly indicated by the patient's risk profile