Ferritin Levels Too Low or Too High: What Your Blood Test Really Means

You've just received your blood test results and one number is flagged — ferritin. Either it's too low, too high, or your doctor mentioned it in passing and you left the appointment not quite sure what it means. You're not alone. Ferritin is one of the most commonly abnormal results on a blood panel, yet it's also one of the least explained. In this guide we cover everything: what ferritin actually is, what the normal range looks like for men, women, and children, what causes low and high ferritin, which symptoms to watch for, and exactly what steps to take next.

What Is Ferritin? (And Why It's Not the Same as Iron)

Ferritin is a protein that stores iron inside your cells and releases it when your body needs it. Think of ferritin as a warehouse — iron is the stock inside. Your serum ferritin test measures how full that warehouse is. This is a critical distinction because you can have a normal serum iron level yet still have dangerously low ferritin — meaning your immediate iron supply looks fine, but your reserves are nearly empty. Your body will drain those reserves over weeks or months, eventually causing iron-deficiency anaemia. This is why ferritin is considered the earliest and most sensitive marker of iron deficiency — it falls long before haemoglobin does.

• Serum iron: the iron currently circulating in your blood — fluctuates hour to hour based on meals
• Ferritin: your long-term iron reserves stored in cells — the most reliable marker of true iron status
• Transferrin saturation: the percentage of iron-carrying proteins that are loaded with iron
• TIBC (Total Iron-Binding Capacity): how much more iron your blood could carry — rises when stores are low

Ferritin Normal Range: Men, Women, and Children

Ferritin reference ranges vary significantly by age and sex, which is why you must compare your result to the ranges printed on your own lab report. The values below are based on WHO and IFCC guidelines and represent typical adult reference ranges:

• Adult men: 30 to 400 ng/mL (µg/L)
• Adult women (premenopausal): 13 to 150 ng/mL — women naturally have lower stores due to menstruation
• Adult women (postmenopausal): 13 to 200 ng/mL
• Children (1–5 years): 6 to 24 ng/mL
• Children (6–15 years): 7 to 140 ng/mL
• Pregnancy: ferritin naturally drops — below 30 ng/mL warrants supplementation

Low Ferritin: Causes, Symptoms, and What to Do

Low ferritin is extremely common — studies estimate that up to 20% of women of reproductive age in the US and UK have depleted iron stores. It does not always mean you have full anaemia (low haemoglobin), but it does mean your body is running on empty and symptoms are likely already present.

• Chronic fatigue and low energy even after a full night's sleep
• Hair loss or excessive shedding — ferritin below 50 ng/mL is strongly linked to telogen effluvium
• Shortness of breath on mild exertion
• Brain fog, poor concentration, and difficulty retaining information
• Restless legs syndrome — an irresistible urge to move the legs at night
• Cold hands and feet, pale skin, brittle nails
• Frequent headaches and dizziness
• Pica — craving non-food items like ice, dirt, or starch

What Causes Low Ferritin?

Low ferritin does not appear randomly — there is always a cause. Identifying and treating the root cause is just as important as supplementing iron.

• Heavy menstrual bleeding: the single most common cause in women of reproductive age — losing more iron each month than diet replaces
• Poor dietary iron intake: strict vegan or vegetarian diets without adequate planning — plant-based (non-haem) iron absorbs far less efficiently than meat-based (haem) iron
• Malabsorption: coeliac disease, inflammatory bowel disease (Crohn's, ulcerative colitis), or gastric bypass surgery impair iron absorption in the gut
• Frequent blood donation: donating more than twice per year can deplete stores in susceptible individuals
• Pregnancy and breastfeeding: iron demand doubles in the third trimester
• Chronic blood loss: peptic ulcers, haemorrhoids, or colorectal cancer can cause slow internal bleeding — especially in men with low ferritin, this must be ruled out
• Intense endurance exercise: "sports anaemia" seen in marathon runners and cyclists

How to Raise Low Ferritin: Treatment Options

Treatment depends entirely on the cause. Simply taking iron tablets without fixing the underlying reason will result in recurring deficiency. Always consult your doctor before starting supplementation.

• Dietary changes: increase haem iron (red meat, liver, shellfish) or pair plant sources (lentils, spinach, tofu, fortified cereals) with vitamin C to boost absorption by up to 67%
• Oral iron supplements: ferrous sulphate 200mg (65mg elemental iron) is the standard first-line treatment — take on an empty stomach for best absorption but this can cause stomach upset
• Every-other-day dosing: research shows taking iron every other day may improve absorption and reduce side effects compared to daily dosing
• IV iron infusion: for those who cannot absorb oral iron or have very severe deficiency — effective and fast
• Avoid iron blockers: coffee, tea, calcium, and antacids taken within 1–2 hours of iron supplements significantly reduce absorption
• Recheck ferritin in 3 months: levels rise slowly — haemoglobin recovers first, then ferritin stores

High Ferritin: What Does It Mean?

A high ferritin result is often more alarming to patients than low ferritin — and rightly so in some cases. However, the most common reason for high ferritin is not iron overload — it is inflammation. Ferritin is an acute-phase reactant, meaning the liver releases it in large quantities whenever there is inflammation, infection, or tissue damage, even if iron stores are normal.

• Ferritin 200–500 ng/mL: mildly elevated — most commonly due to inflammation, metabolic syndrome, or alcohol use
• Ferritin 500–1,000 ng/mL: moderately elevated — warrants further investigation for liver disease or hereditary haemochromatosis
• Ferritin above 1,000 ng/mL: significantly elevated — requires urgent evaluation
• Ferritin above 10,000 ng/mL: seen in haemophagocytic lymphohistiocytosis (HLH) — a rare but life-threatening condition

What Causes High Ferritin?

The causes of elevated ferritin range from benign to serious — which is why further investigation is always needed.

• Chronic inflammation: rheumatoid arthritis, lupus, IBD, chronic infections — ferritin rises as part of the inflammatory response
• Non-alcoholic fatty liver disease (NAFLD): the most common liver condition in the US and UK — ferritin is frequently elevated
• Alcohol use: even moderate regular drinking raises ferritin levels
• Metabolic syndrome and obesity: insulin resistance drives ferritin production independently of iron stores
• Hereditary haemochromatosis (HH): a genetic condition causing excessive iron absorption — affects 1 in 200 people of Northern European descent and is frequently missed
• Type 2 diabetes: elevated ferritin is found in up to 40% of diabetic patients
• Hyperthyroidism: overactive thyroid can raise ferritin
• Certain cancers: lymphoma, leukaemia, and liver cancer can cause very high ferritin
• Recent infection or surgery: ferritin spikes temporarily after any acute illness

Hereditary Haemochromatosis — The Hidden Diagnosis

Hereditary haemochromatosis (HH) is the most common genetic disorder in people of Northern European ancestry, yet it takes an average of 10 years to diagnose. It causes the body to absorb far too much iron from food, which accumulates in organs including the liver, heart, and pancreas — causing cirrhosis, heart failure, diabetes, and joint damage if untreated. The good news: if caught early, treatment is simple and highly effective.

• Symptoms: joint pain (especially knuckles), fatigue, abdominal pain, bronze or grey skin tone, reduced libido
• Typical ferritin: often above 500–1,000 ng/mL with transferrin saturation above 45%
• Diagnosis: HFE gene test (C282Y and H63D mutations) confirms the diagnosis
• Treatment: therapeutic phlebotomy (regular blood removal) — essentially the same as donating blood every 1–3 months
• Who to test: first-degree relatives of anyone diagnosed with HH should be screened

When to See a Doctor About Your Ferritin Result

Not every abnormal ferritin result requires urgent action, but certain findings always warrant prompt medical attention.

• Ferritin below 13 ng/mL with symptoms — low iron stores confirmed, treatment needed
• Ferritin below 30 ng/mL in a pregnant woman — supplementation should begin immediately
• Ferritin above 500 ng/mL — needs investigation for liver disease or haemochromatosis
• Any man or postmenopausal woman with low ferritin — gastrointestinal bleeding must be excluded
• Ferritin above 1,000 ng/mL — requires urgent specialist referral
• High ferritin with elevated liver enzymes (ALT/AST) — suggests liver involvement
• High ferritin with joint pain and bronze skin — suspect haemochromatosis

Check Your Ferritin Result with LabSense AI — Free

Received your ferritin result and not sure what it means for you? Enter your ferritin level, transferrin saturation, serum iron, or any other marker into LabSense AI and get an instant plain-English explanation — including whether your result is normal for your age and sex, what the likely causes are, and whether you need to follow up with a doctor. No sign-up required. Trusted by patients across the US, UK, and 50+ countries.