The short answer: the most common iron deficiency symptoms are tiredness and lack of energy, shortness of breath, pale skin, headaches and noticeable heartbeats, according to the NHS. Others include cold hands and feet, dizziness, brittle or spoon-shaped nails, hair loss and cravings for ice or other non-food items. Mild iron deficiency often causes no symptoms, so a blood test is the only way to know.
Iron lets your body make hemoglobin, the part of red blood cells that carries oxygen. That’s why so many of the signs come back to tiredness and breathlessness.
What are the symptoms of iron deficiency?
Symptoms usually start mild and worsen over time, Cleveland Clinic says. Here’s what three major sources list:
| Symptom | NHS | NHLBI (NIH) | Cleveland Clinic |
|---|---|---|---|
| Tiredness, lack of energy | Yes | Yes | Yes |
| Shortness of breath | Yes | Yes | Yes |
| Pale skin | Yes | Yes | Yes |
| Headaches | Yes | No | Yes |
| Palpitations or a fast heartbeat | Yes | No | Yes |
| Dizziness or lightheadedness | No | Yes | Yes |
| Cold hands and feet | No | Yes | Yes |
| Chest pain | No | Yes, if more serious | Occasionally |
| Craving ice, paper or dirt (pica) | Less common | No | Yes |
| Spoon-shaped nails | Less common | No | Yes |
| Sore tongue or sores at the corners of the mouth | Less common (mouth sores) | No | Yes (sore tongue) |
| Hair loss | Less common | No | No |
| Restless legs | Less common | A complication if untreated | A complication |
The NHS also lists itching, ringing in the ears, food tasting strange and trouble swallowing, and Cleveland Clinic adds irritability and muscle cramps. NIH adds stomach upset and problems with concentration and memory.
What are the first signs of low iron?
Often there are none. NIH says getting too little iron causes no obvious symptoms in the short term, because your body draws on iron stored in your liver, spleen, muscles and bone marrow. Symptoms tend to show once those stores run low.
When signs appear, they’re easy to blame on a busy life: tiredness, getting out of breath on stairs, looking paler or feeling the cold. Our guide to why you’re always tired covers the other common causes of fatigue.
Is iron deficiency the same as anemia?
No. Iron deficiency means your iron stores are low. Iron deficiency anemia is the later stage, when your hemoglobin has dropped below normal. Cleveland Clinic describes three stages. First, your iron stores fall. Next, your bone marrow makes red blood cells without enough hemoglobin. Finally, hemoglobin drops below normal and signs of anemia often appear.
It’s the most common type of anemia, says NHLBI, but not the only one. Low B12 or folate can also cause anemia, and our guide to foods high in B12 explains that one.
What causes low iron?
Low iron usually comes from losing blood, needing more iron, absorbing too little or eating too little. Bleeding is the most common reason, Cleveland Clinic says.
- Heavy periods. The NHS calls heavy periods and pregnancy very common causes.
- Pregnancy and childbirth. Pregnancy raises your iron needs, and childbirth can bring blood loss.
- Bleeding in the gut. Ulcers, inflammatory bowel disease and, less often, bowel or stomach cancer can cause hidden bleeding. Regular use of aspirin or NSAIDs such as ibuprofen can cause it too, the NHS and NHLBI say. Don’t stop a prescribed medicine on your own; ask your doctor instead.
- Poor absorption. Celiac disease, Crohn’s disease, ulcerative colitis, H. pylori infection and stomach or weight loss surgery can all reduce how much iron you absorb, NHLBI says.
- Diet. People who eat no meat, poultry or seafood need almost twice as much iron, NIH says, because plant iron is harder to absorb.
- Other causes. Frequent blood donation, endurance sports and kidney disease.
Cleveland Clinic says suddenly becoming low in iron can point to stomach ulcers or colon polyps, and sometimes to cancer of the digestive tract. If the reason isn’t clear, the NHS says your doctor may test a stool sample for hidden blood or refer you on.
How do you test for iron deficiency?
Iron deficiency is diagnosed with a blood test. NHLBI says your doctor will usually check a complete blood count (CBC), your hemoglobin, your blood iron level and your ferritin.
Ferritin is the protein that stores iron, so a ferritin test shows how much iron you have in reserve, MedlinePlus explains. Since stores fall before hemoglobin does, in Cleveland Clinic’s stages, ferritin can flag low iron early. Inflammation, such as from an infection or surgery, can raise ferritin, and some medicines can shift it too, so ask your doctor what your result means. You may be asked to fast for 12 hours first.
MedlinePlus says it can also check iron before symptoms start if you’re at higher risk, such as with heavy periods.
How much iron do you need a day?
Most adult men need 8 mg of iron a day and women 19 to 50 need 18 mg, according to the NIH Office of Dietary Supplements. Here are the official amounts for teens and adults:
| Life stage | Iron per day |
|---|---|
| Teen boys 14 to 18 | 11 mg |
| Teen girls 14 to 18 | 15 mg |
| Men 19 and up | 8 mg |
| Women 19 to 50 | 18 mg |
| Women 51 and up | 8 mg |
| Pregnancy | 27 mg |
| Breastfeeding (19 and up) | 9 mg |
If you eat no meat, poultry or seafood, NIH says you need about 1.8 times these amounts. The Daily Value on food labels is 18 mg.
What foods are high in iron?
Shellfish, liver, beans, lentils, cooked spinach and fortified cereals are among the highest. Figures are from USDA FoodData Central; % DV is based on 18 mg:
| Food | Portion | Iron (mg) | % DV | Iron type |
|---|---|---|---|---|
| Instant oatmeal, fortified (varies by brand) | 1 cup cooked | 14.0 | 78% | Non-heme |
| Oysters, cooked | 3 oz | 7.8 | 43% | Both |
| White beans, cooked | 1 cup | 6.6 | 37% | Non-heme |
| Lentils, cooked | 1 cup | 6.6 | 37% | Non-heme |
| Spinach, boiled | 1 cup | 6.4 | 36% | Non-heme |
| Mussels, cooked | 3 oz | 5.7 | 32% | Both |
| Beef liver, pan-fried | 3 oz | 5.2 | 29% | Both |
| Chickpeas, cooked | 1 cup | 4.7 | 26% | Non-heme |
| Kidney beans, cooked | 1 cup | 3.9 | 22% | Non-heme |
| Dark chocolate, 70 to 85% | 1 oz | 3.4 | 19% | Non-heme |
| Firm tofu | ½ cup | 3.4 | 19% | Non-heme |
| Sardines, canned in oil | 1 can (3.75 oz) | 2.7 | 15% | Both |
| Ground beef, 85% lean, cooked | 3 oz | 2.2 | 12% | Both |
| Chicken breast, roasted | 3 oz | 0.9 | 5% | Both |
Meat, poultry and seafood contain both heme and non-heme iron, NIH says; plants and fortified foods have non-heme only. Lentils and beans also bring fiber and protein and star in our high-protein soups.
How do you increase iron absorption?
Eat plant sources of iron with vitamin C or with a little meat, poultry or seafood. Both help your body absorb non-heme iron, NIH says. Heme iron, found only in meat, poultry and seafood, is absorbed better than non-heme iron from plants and fortified foods.
Easy pairings, with vitamin C figures from USDA:
- Lentil or bean soup with a cup of chopped red bell pepper (about 190 mg vitamin C) in a salad on the side
- Fortified oatmeal with a cup of strawberries (about 89 mg)
The NHS suggests less tea, coffee, milk and dairy, and fewer high-phytate foods such as wholegrain cereals, if diet is part of the problem. NIH says calcium may reduce absorption of both kinds of iron. A simple fix is to have your tea or coffee between meals.
Should you take iron supplements without a test?
It’s best not to. Tiredness has many causes, and guessing can delay finding the reason you’re low, such as bleeding in the gut. Cleveland Clinic says supplements are only a temporary fix if the cause isn’t treated.
Too much iron can also hurt. NIH says high doses can cause stomach upset, constipation, nausea and vomiting, and that the upper limit for adults from all sources is 45 mg a day unless a doctor advises otherwise. People with hemochromatosis, an inherited condition that makes the body store too much iron, should avoid iron supplements. Keep iron products away from children: NIH says accidental overdose is a leading cause of fatal poisoning in children under 6.
If a test shows you’re low, your doctor will choose a treatment. The NHS says treatment usually lasts about 6 months, and Cleveland Clinic says people often notice a difference in two to three weeks.
When should you see a doctor about low iron?
See a doctor if you think you might have iron deficiency, the NHS says. NHLBI says more serious iron deficiency anemia can cause chest pain and shortness of breath, so get medical help right away for either. Sleepy after meals too? Read why you’re tired after eating. For the full food list, see foods high in iron.
Your next step
If the symptoms sound familiar, book a blood test and ask for ferritin to be included. Meanwhile, pair one iron-rich food with a vitamin C food each day. For planned meals, the Menopause Meal Plan below has four weeks of high-protein meals and grocery lists, or start with our free 7-day meal plan.
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Quick questions
What does low iron feel like?
Low iron usually feels like tiredness that rest doesn’t fix, often with getting out of breath easily, looking paler, feeling cold or having headaches. The NHS also lists noticeable heartbeats. Some people crave ice or have brittle nails. Mild iron deficiency can cause no symptoms at all, so a blood test is the only way to be sure.
Can low iron cause hair loss?
Yes, low iron can cause hair loss. The NHS lists noticing more hair coming out when you brush or wash it as a less common symptom of iron deficiency anaemia. Hair loss has many other causes too, so ask your doctor for a blood test that includes ferritin before assuming it’s iron.
Can low iron cause anxiety or dizziness?
Low iron can cause dizziness and lightheadedness, according to NHLBI and Cleveland Clinic. Cleveland Clinic also lists irritability, and the NHS lists palpitations, which can feel a lot like anxiety. If you feel dizzy, faint or have a racing heartbeat, see a doctor rather than assuming the cause.
What is the fastest way to raise iron levels?
The right treatment depends on how low you are and why, so it should come from your doctor after a blood test. NHLBI says iron pills usually take three to six months to restore iron levels, while IV iron can work in one or a few sessions. Eating iron-rich foods with vitamin C helps too.
What drinks block iron absorption?
Tea, coffee and milk can make it harder to absorb iron, the NHS says, especially in large amounts. NHLBI names black tea, and NIH says calcium may reduce absorption of both heme and non-heme iron. Drinking tea or coffee between meals, rather than with them, is a simple way around it.
Is iron deficiency common?
Yes, iron deficiency anemia is the most common type of anemia, according to NHLBI and the NHS. NIH says most people in the United States get enough iron, but deficiency is more common in young children, women with heavy periods, pregnant women, frequent blood donors and people with gut disorders.
This article is general information, not medical advice. Only a blood test can show whether you’re low in iron, and the cause should be found and treated by your doctor. Don’t start iron supplements without a test or stop any medicine without talking to your doctor, and keep iron products away from children.
Sources
- NHS. Iron deficiency anaemia
- NHLBI. Iron-Deficiency Anemia
- NHLBI. Anemia: Symptoms
- Cleveland Clinic. Iron-Deficiency Anemia
- NIH Office of Dietary Supplements. Iron: Fact Sheet for Consumers
- NIH Office of Dietary Supplements. Iron: Fact Sheet for Health Professionals
- MedlinePlus. Ferritin Blood Test
- USDA FoodData Central. SR Legacy (2018)