Iron levels: why you're tired even after sleeping 8 hours

WHAT IRON ACTUALLY DOES IN YOUR BODY

Iron isn't just another mineral. It's the delivery system for oxygen.

Here's what happens:

STEP 1: IRON CREATES HEMOGLOBIN

Hemoglobin is the protein in red blood cells that carries oxygen from your lungs to every cell in your body.

Iron is the core component of hemoglobin. Without enough iron, your body can't make enough hemoglobin.

Low hemoglobin = less oxygen delivered to your cells.

STEP 2: CELLS USE OXYGEN FOR ENERGY

Every cell in your body needs oxygen to produce energy (ATP).

Brain cells need oxygen to think clearly. Muscle cells need oxygen to move and function. Heart cells need oxygen to pump blood.

When oxygen delivery drops, energy production crashes.

Result: You're exhausted. Your brain is foggy. Your muscles feel weak. Your heart has to work harder.

STEP 3: IRON STORES OXYGEN IN MUSCLES

Iron is also part of myoglobin, which stores oxygen in your muscles.

When you move, your muscles pull from this oxygen reserve.

Low iron = depleted oxygen reserves = your muscles fatigue instantly.

This is why people with low iron get winded going up stairs or carrying groceries. It's not fitness. It's oxygen.

WHY YOU'RE TIRED WITH LOW IRON (EVEN AFTER 8 HOURS OF SLEEP)

Sleep restores your body. But it doesn't create oxygen-carrying capacity.

If your blood can't carry enough oxygen, sleep won't fix your energy.

HERE'S WHAT HAPPENS WITH LOW IRON:

Your brain isn't getting enough oxygen. Result: Brain fog, poor concentration, memory issues, headaches.

Your muscles aren't getting enough oxygen. Result: Weakness, heavy legs, getting winded easily.

Your heart has to pump harder to deliver the limited oxygen you have. Result: Racing heart, shortness of breath, chest tightness.

Your body prioritizes vital organs. Result: Everything else (digestion, immune function, hair growth) gets deprioritized.

You can sleep 10 hours and wake up exhausted because your cells are oxygen-starved.

No amount of rest fixes an oxygen delivery problem.

THE SIGNS YOU HAVE LOW IRON

Most people don't realize they're low in iron. They just think they're tired or stressed.

Here are the signs:

ENERGY SYMPTOMS:

• Constant fatigue (even after full night's sleep)

• Need multiple cups of coffee to function

• Afternoon crash that feels debilitating

• Exhausted after minimal physical activity

PHYSICAL SYMPTOMS:

• Pale skin (especially inside eyelids, under nails)

• Cold hands and feet (even in warm rooms)

• Brittle nails that break easily

• Hair loss or thinning hair

• Restless legs at night

• Frequent headaches

COGNITIVE SYMPTOMS:

• Brain fog (can't think clearly)

• Poor concentration and focus

• Memory problems

• Irritability and mood swings

CARDIOVASCULAR SYMPTOMS:

• Heart palpitations or racing heart

• Shortness of breath (especially with activity)

• Dizziness when standing up

UNUSUAL SYMPTOMS:

• Craving ice or non-food items (dirt, clay, starch)

• Sore or swollen tongue

• Cracks at corners of mouth

• Frequent infections (low iron weakens immune system)

If you have 3+ of these symptoms, your iron is probably low.

WHY YOUR IRON IS PROBABLY LOW

Iron deficiency is extremely common, especially in women. Here's why:

CAUSE 1: MENSTRUAL BLOOD LOSS

This is the number one reason women have low iron.

Every period, you lose blood. Blood contains iron.

Heavy periods = significant iron loss every month.

If you're not replacing that iron through diet, your stores slowly deplete.

Over time: Fatigue sets in. You think it's normal. It's not.

CAUSE 2: NOT EATING ENOUGH IRON-RICH FOODS

Most people don't eat enough iron, period.

Modern diets are low in red meat (highest iron source). Vegetarian and vegan diets are even lower in absorbable iron.

Recommended daily iron:

• Men: 8mg

• Women (menstruating): 18mg

• Pregnant women: 27mg

Most women get 10-12mg per day. Not enough to replace monthly losses.

CAUSE 3: POOR IRON ABSORPTION

Even if you eat iron, your body might not absorb it.

Factors that block iron absorption:

• Drinking coffee or tea with meals (tannins block absorption)

• Eating calcium-rich foods with iron (calcium competes for absorption)

• Low stomach acid (needed to absorb iron)

• Digestive issues (celiac, Crohn's, IBS damage gut lining)

• Antacids and acid-blocking medications

You could be eating iron-rich foods and still be deficient because your gut isn't absorbing it.

CAUSE 4: PREGNANCY AND BREASTFEEDING

Pregnancy dramatically increases iron needs (your blood volume increases 50%).

Breastfeeding depletes iron further.

Many women enter pregnancy already low in iron. By the end, they're severely deficient.

Post-pregnancy exhaustion isn't just sleep deprivation. It's often iron deficiency.

CAUSE 5: INTENSE EXERCISE

Athletes lose iron through:

• Sweat

• Foot strike hemolysis (red blood cells breaking from impact)

• Gastrointestinal bleeding (from intense training)

If you're training hard and constantly tired, check your iron.

CAUSE 6: BLOOD DONATION

Donating blood removes 200-250mg of iron from your body.

It takes months to replenish that through diet alone.

If you donate regularly and feel exhausted afterward, your iron stores are depleted.

THE STAGES OF IRON DEFICIENCY

Iron deficiency happens in stages. Most people don't notice until Stage 3.

STAGE 1: DEPLETED IRON STORES

Your ferritin (stored iron) is low, but hemoglobin is still normal.

Symptoms: Mild fatigue, maybe nothing noticeable yet.

Blood test: Ferritin below 30 ng/mL (some experts say below 50).

Most doctors won't diagnose this as a problem. But you're already running low.

STAGE 2: EARLY IRON DEFICIENCY

Your body is using up remaining iron stores. Hemoglobin starts to drop slightly.

Symptoms: Noticeable fatigue, brain fog, weakness.

Blood test: Ferritin very low (below 15), hemoglobin at lower end of normal.

Doctors might say "you're fine" because hemoglobin isn't technically anemic yet.

But you feel terrible.

STAGE 3: IRON DEFICIENCY ANEMIA

Your hemoglobin is now too low. Your blood can't carry enough oxygen.

Symptoms: Severe fatigue, shortness of breath, pale skin, rapid heartbeat.

Blood test: Low hemoglobin (below 12 for women, below 13 for men), very low ferritin.

This is when doctors finally diagnose you. But you've been suffering for months or years.

WHY DOCTORS MISS THIS

Here's the frustrating part: You go to the doctor. You say you're exhausted.

They run a basic blood panel. Hemoglobin comes back "normal."

Doctor says: "Your blood work is fine. Maybe you need more sleep."

But they didn't check ferritin.

Hemoglobin measures current red blood cell levels. Ferritin measures iron stores.

You can have "normal" hemoglobin and depleted ferritin. Your body is burning through its last reserves to keep hemoglobin normal.

By the time hemoglobin drops, you're in Stage 3 (anemia). You've been suffering in Stage 1 and 2 for months.

Always ask for a ferritin test, not just hemoglobin.

Optimal ferritin for energy: 50-100 ng/mL (not just "above 15").

HOW TO FIX LOW IRON

Fixing iron deficiency takes time. Your body can only absorb so much iron at once.

STEP 1: GET TESTED

Don't guess. Get a blood test.

Ask for:

• Hemoglobin

• Ferritin

• Serum iron

• Total iron-binding capacity (TIBC)

This gives a complete picture of your iron status.

STEP 2: EAT MORE IRON-RICH FOODS

There are two types of iron:

Heme iron (from animals): Highly absorbable (15-35% absorption)

• Red meat (beef, lamb)

• Organ meats (liver - highest source)

• Poultry (chicken, turkey - dark meat has more)

• Fish (salmon, tuna, sardines)

• Shellfish (oysters, clams)

Non-heme iron (from plants): Poorly absorbable (2-20% absorption)

• Spinach, kale, Swiss chard

• Lentils, beans, chickpeas

• Tofu and tempeh

• Quinoa

• Fortified cereals

• Pumpkin seeds

If you're low in iron, you need heme iron. Plant sources alone won't fix deficiency quickly.

Vegetarians and vegans: You need significantly more dietary iron (almost double) because absorption is so low.

STEP 3: BOOST IRON ABSORPTION

Pair iron-rich foods with:

Vitamin C: Dramatically increases iron absorption

• Bell peppers

• Citrus fruits (oranges, grapefruit)

• Strawberries

• Tomatoes

• Broccoli

Example: Steak with bell peppers, or lentils with lemon juice.

Avoid these with iron-rich meals:

Coffee and tea (wait 1-2 hours after eating) Calcium-rich foods (don't eat dairy with iron) High-fiber foods (can bind iron)

STEP 4: CONSIDER IRON SUPPLEMENTS

If your ferritin is below 30, food alone will take months to fix it.

Iron supplements work faster.

Types of iron supplements:

Ferrous sulfate: Most common, cheap, but causes stomach issues (constipation, nausea)

Ferrous bisglycinate (chelated iron): More expensive, but easier on stomach, better absorbed

Heme iron supplements: Most absorbable, gentle on stomach, but pricey

Dosage:

• Start with 25-50mg elemental iron per day

• Take with vitamin C (orange juice or a vitamin C tablet)

• Take on empty stomach if tolerated, or with small meal if it bothers your stomach

Important: Don't mega-dose iron. More isn't better. Your body can only absorb so much at once.

STEP 5: ADDRESS UNDERLYING CAUSES

If you have:

Heavy periods: Talk to your doctor about birth control or other treatments to reduce bleeding

Digestive issues: Get checked for celiac, IBS, low stomach acid

Vegetarian/vegan diet: Be extra vigilant about iron-rich plant foods + vitamin C

Regular blood donation: Space out donations, supplement iron between donations

WHEN TO SEE A DOCTOR

You should see a doctor if:

Low iron doesn't improve after 3 months of supplementation. This could mean you're not absorbing iron or you're losing blood somewhere (internal bleeding, ulcers).

Hemoglobin is very low (below 10). This is severe anemia. You might need iron infusions (IV iron).

You have unexplained iron deficiency as a man or post-menopausal woman. Men and post-menopausal women shouldn't be low in iron (no monthly blood loss). This suggests internal bleeding (GI bleed, ulcers, cancer). Needs investigation.

You have extreme fatigue plus other concerning symptoms (unexplained weight loss, night sweats, blood in stool).

Iron deficiency can mask other conditions. Rule out serious causes.

THE REAL TRUTH ABOUT IRON AND ENERGY

You can do everything right for sleep and still be exhausted if your iron is low.

Sleep hygiene doesn't fix an oxygen delivery problem.

Meditation doesn't increase hemoglobin.

Caffeine masks the fatigue temporarily but doesn't solve anything.

Your cells need oxygen. Iron delivers that oxygen. Without enough iron, your cells are starving.

The exhaustion isn't in your head. It's in your blood.

Once your iron is restored, energy returns. Brain fog clears. You don't need three cups of coffee to function. You can exercise without feeling like you're dying.

But you have to check your levels. You have to address it.

Most people walk around iron-deficient for years, thinking they're just "tired people."

You're not a tired person. You're a person with low iron.

Fix the iron. Fix the energy.

ONE MORE THING YOU CAN DO THIS WEEK

Don't try to overhaul your entire diet overnight.

Just do ONE thing this week:

Eat one iron-rich meal this week.

Options:

Steak with bell peppers and broccoli (heme iron + vitamin C)

Lentil soup with tomatoes and lemon juice (non-heme iron + vitamin C)

Chicken thighs with spinach sautéed in garlic

Salmon with roasted Brussels sprouts

One meal. That's it.

Notice how you feel. Then add another next week.

And if you're constantly exhausted despite sleeping well, get your ferritin checked. Not just hemoglobin. Ferritin.

Small changes compound into major energy improvements.

⭐ RATE TODAY’S EDITION

Here's to waking up with actual energy!

Sarah

P.S. - The single most important thing? Get your ferritin tested. Not just hemoglobin. Ferritin shows your iron stores. If it's below 50, you've found why you're tired all the time. Everything else - sleep, stress management, coffee - won't fix an iron deficiency. Fix the root cause first.