Dr Libby: Heart Racing? Here’s What Your Body Might Be Trying To Tell You

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By Dr Libby Weaver

Saturday May. 31, 2025

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Dr Libby on what you need to know about a racing heart. Photo / Getty Images

Heart racing? Here’s what your body might be trying to tell you, writes Dr Libby.

We all know that feeling – a heart that suddenly beats a little too fast. Maybe it happens when you’re lying in bed at night, trying to fall asleep. Or in the middle of a

You body is giving you important feedback

Before we dive into the “why”, let’s take a moment to acknowledge something important: your body is incredibly wise. It’s constantly working to keep you alive, adapting moment to moment to whatever you’re facing – even if it doesn’t always feel that way. Symptoms are your body’s language. They’re feedback. They’re invitations to listen more deeply. So what might a racing heart be trying to tell you?

One of the lesser-known causes of a racing heart, especially in women, is iron deficiency. Iron is critical for the production of haemoglobin, a protein in your red blood cells that carries oxygen throughout your body. When iron levels are low, your body struggles to deliver enough oxygen to your tissues. Your heart, sensing this, compensates by beating faster to try to circulate what oxygen there is more quickly.

If you’ve also noticed fatigue, shortness of breath on exertion, brain fog, anxiety, or even hair loss, it’s worth exploring whether iron could be playing a role. You don’t have to have full-blown anaemia for these symptoms to occur; even mild depletion can have a profound impact on how you feel. Many people live with low iron for years without realising it, often blaming their symptoms on ageing, stress, or simply being busy. Yet restoring iron levels can transform not just your energy, but your mood, sleep, focus – and yes, even those unsettling heart palpitations.

A racing heart and anxiety

Of course, a racing heart is also one of the hallmark symptoms of anxiety. But anxiety isn’t just “in your head” – it’s a whole-body experience, deeply rooted in your biochemistry and your nervous system. When you perceive a threat, whether it’s a looming deadline, a difficult conversation, or even a stream of worried thoughts, your body activates the sympathetic nervous system – the “fight or flight” response. Your heart rate speeds up. Your breathing becomes shallow. Blood is redirected away from digestion toward your periphery, preparing you to run or fight. This response was designed to keep us alive in the face of immediate danger. The challenge today is that for many people, the threat isn’t a lion chasing them – it’s the relentless, unyielding pace of modern life. And because the stress isn’t quickly resolved, the body stays switched on, often for far longer than it’s meant to.

The word “stress” is so common now that we sometimes forget what it really means. Stress isn’t just a bad day at work. It’s anything that asks your body to adapt – an intense workout, a difficult conversation, poor sleep, a blood sugar rollercoaster, unprocessed emotions, even environmental toxins. All of these factors place demands on your system. While the body is wonderfully resilient, stress accumulates if we don’t allow enough recovery time or we don’t replenish it with adequate nourishment. It’s like making too many withdrawals from your energy bank account without enough deposits. Eventually, the body starts to signal that something needs attention – through symptoms like fatigue, anxiety, digestive issues, low mood, or, you guessed it, a racing heart.

Key nutrients to consider

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Over time, chronic nervous system activation, often driven by ongoing stress and unresolved anxiety, can deplete key nutrients – including magnesium, zinc, B vitamins, vitamin C and, importantly, iron. All of these are crucial for emotional steadiness, energy production and healthy heart rhythm regulation. When the body is under constant pressure, it becomes less equipped to stay calm and a racing heart may surface more readily.

The most important thing to remember is that symptoms are not a sign that your body is broken. They are signs that your body is doing everything it can to communicate with you, asking for attention, support and nourishment. If you experience heart palpitations, it can be helpful to gently explore: could my iron levels be low? Am I relying too heavily on stress hormones to get through the day? Is my nervous system getting opportunities to rest and reset? Am I nourishing myself with foods that support calm and resilience?

Addressing low iron, supporting your nervous system and managing stress doesn’t have to be complicated. It can be as simple as including iron-containing whole foods – like grass-fed organic meat, lentils, leafy greens and seaweed – and pairing them with vitamin C-rich foods to enhance absorption. Practising slow, diaphragmatic breathing for even a few minutes each day can help rewire your nervous system toward calm.

Small changes make a difference

Prioritising restorative sleep, gentle movement and being mindful of caffeine and alcohol intake can also make a profound difference. Creating small, meaningful moments of joy and spaciousness in your day – even a few minutes of sunlight on your face or a quiet walk – can help refill your energy bank account in ways that matter.

Above all, be compassionate with yourself. Healing – whether from low iron, stress or anything else – takes time. Your body is always working for you, never against you. So if your heart is racing, listen. Get curious. Ask what it might need. Often, the answers are far simpler – and more powerful – than we realise.

Dr Libby Weaver PhD is a nutritional biochemist, 13 times bestselling author and international keynote speaker. For more on supporting yourself inside and out visit Drlibby.com