{ "presentation": "complete-card", "format_version": 3, "overview": "Ferritin is a protein that stores iron. A ferritin blood test helps estimate your iron reserves and can be part of investigating fatigue or weakness. Low and high results both need interpretation alongside your health history.", "overview_sources": "MedlinePlus · 2025", "overview_source_ids": [ "self22b8-ferritin-medline" ], "sections": [ { "role": "explanation", "title": "What the number tells you", "items": [ { "label": "Iron stores and anemia are different questions.", "text": "A complete blood count (CBC) measures hemoglobin to assess anemia. Low ferritin can reveal depleted reserves before hemoglobin falls.", "source": "BC Guidelines · 2019", "source_ids": [ "self22b8-ferritin-deficiency" ] }, { "label": "A low result can mean depleted reserves.", "text": "WHO uses below 15 µg/L for iron deficiency in apparently healthy adults aged 20–59, and below 70 µg/L with infection or inflammation. These are context-dependent diagnostic cutoffs, not personal targets or permission to take iron.", "source": "WHO", "source_ids": [ "self22b8-ferritin-who" ] }, { "label": "Inflammation can conceal low iron stores.", "text": "Inflammation can raise ferritin despite depleted reserves. Clinicians may use transferrin saturation—the proportion of an iron-carrying protein carrying iron—to clarify the picture.", "source": "BC Guidelines · 2019", "source_ids": [ "self22b8-ferritin-deficiency" ] }, { "label": "Testing involves a blood sample.", "text": "A clinician or lab takes blood from a vein. Preparation depends on the ordered tests; the provider may request fasting. The draw itself usually takes less than five minutes.", "source": "MedlinePlus · 2025", "source_ids": [ "self22b8-ferritin-medline" ] }, { "label": "Follow-up investigates why stores are low.", "text": "Diet, donation, heavy periods, bleeding and poor absorption are possible causes. Unexplained deficiency in men or after menopause may require gastrointestinal investigation.", "source": "BC Guidelines · 2019", "source_ids": [ "self22b8-ferritin-deficiency" ] } ] }, { "role": "benefits", "title": "What testing can help with", "items": [ { "label": "It can identify an iron-related problem.", "text": "Ferritin can help a clinician investigate suspected deficiency or overload. The benefit is information that guides care; having a test does not itself restore energy.", "source": "MedlinePlus · 2025", "source_ids": [ "self22b8-ferritin-medline" ] }, { "label": "Follow-up tests can track a treatment response.", "text": "Timing depends on severity and cause; stores can recover more slowly than hemoglobin. Persistent low results prompt reassessment of bleeding, absorption or diagnosis.", "source": "BC Guidelines · 2019", "source_ids": [ "self22b8-ferritin-deficiency" ] } ] }, { "role": "cautions", "title": "Good to know before chasing a number", "items": [ { "label": "High ferritin does not automatically mean iron overload.", "text": "Inflammation, liver disease and other conditions can raise it. Clinical history, transferrin saturation and further testing help distinguish causes; a high value is not a fitness achievement.", "source": "BC Guidelines · 2021", "source_ids": [ "self22b8-ferritin-high" ] }, { "label": "Iron supplements have real risks.", "text": "Excess iron can cause stomach problems and serious poisoning, especially in children. It can also interfere with medicines such as levothyroxine. A ferritin screenshot is not a treatment plan.", "source": "NIH ODS · 2023", "source_ids": [ "self22b8-ferritin-ods" ] }, { "label": "A commercial panel still needs clinical follow-up.", "text": "Function lists ferritin among its nutrient tests and states that its service does not provide diagnosis or treatment. A panel result still belongs in a discussion with a licensed clinician.", "source": "Function Health", "source_ids": [ "self22b8-ferritin-function" ] } ] }, { "role": "community", "title": "From fatigue, training and follow-up discussions", "intro": "These are personal reports and discussion, not proof that ferritin caused every symptom or that someone else's treatment will work for you.", "items": [ { "label": "Normal hemoglobin can feel like an incomplete answer.", "text": "A half-marathon runner reported ferritin of 21 with normal hemoglobin after even short runs became difficult. Replies ranged from improved energy to trouble keeping levels up and difficulty qualifying for infusions.", "source": "Community · Reddit r/XXRunning", "source_ids": [ "self22b8-ferritin-normal-hb" ] }, { "label": "Better numbers do not always mean a quick return to running.", "text": "One runner described ferritin rising from 0 to 36 over four months but only slight running improvement after blood donation. Other replies described substantially better energy after treatment. These accounts do not establish a recovery timetable.", "source": "Community · Reddit r/running", "source_ids": [ "self22b8-ferritin-slow-recovery" ] }, { "label": "Tolerability varies, even within the same discussion.", "text": "In one running thread, some reported no bowel problems with oral iron; another described every preparation tried upsetting their gut. A commenter felt better within two weeks of a clinician-recommended infusion, while others described slow progress or limited access.", "source": "Community · Reddit r/XXRunning · 2026", "source_ids": [ "self22b8-ferritin-mixed-treatment" ] }, { "label": "Stomach symptoms can interrupt a treatment plan.", "text": "An account described bloating, loose stools and nausea after prescribed iron, followed by contacting hematology. The poster also had substantial gastrointestinal history, so attributing every symptom to iron would oversimplify the story.", "source": "Community · Reddit r/Anemic", "source_ids": [ "self22b8-ferritin-stomach" ] }, { "label": "Hair shedding and feeling cold also bring people to ferritin.", "text": "Accounts include fatigue, hair worries and disappointing training despite an ordinary blood count, across heavy-period, postpartum, plant-forward and male experiences. Those concerns are reasons people seek explanations, not confirmation of an iron diagnosis.", "source": "Community", "provenance": "preserved-community-record" }, { "label": "“Optimal” ranges can become a moving goalpost.", "text": "People compare lab intervals with runner or influencer targets and disagree about what feels normal. Some describe relief from finding an explanation; others spiral into repeated checks and new supplement protocols.", "source": "Community", "provenance": "preserved-community-record" }, { "label": "The appointment is easier with the actual report.", "text": "People describe keeping the value, units, date and printed range alongside symptoms, menstrual flow, mileage, diet, gut history and supplements already used. Some ask about ferritin with other labs; cost and coverage affect access.", "source": "Community", "provenance": "preserved-community-record" }, { "label": "Retesting and training changes are part of the follow-up conversation.", "text": "Reports describe clinician-planned checks over weeks or months, recording energy and run quality, and easing training during severe fatigue. Coffee or calcium timing can complicate prescribed routines; sleep and adequate food still enter the discussion.", "source": "Community", "provenance": "preserved-community-record" } ], "groups": [ { "title": "Symptoms and recovery beyond the lab number", "item_indices": [ 0, 1, 4 ] }, { "title": "Treatment tolerability", "item_indices": [ 2, 3 ] }, { "title": "Online targets and clinical follow-up", "item_indices": [ 5, 6, 7 ] } ] } ], "related": [ "function-superpower", "sleep-hours", "cycle-tracking", "eat-something" ] }