Quick answer

Feeling tired-but-wired, having constant low-grade worry and a racing heart after giving birth could signal you have anxiety or physical depletion or both. Sleep deprivation, dehydration, swings in blood sugar and a hypothalamic-pituitary-adrenal (HPA) axis on overdrive mimic the symptoms of anxiety. Both of these can look the same on the outside, but recognizing what is actually happening helps point to the best path to feel better. 

Why postpartum symptoms get labeled as "just anxiety" so fast

When you come home after giving birth, you may be surprised at the impact of the physiological stressors: loss of blood, hormonal shifts, lack of sleep, dehydration, low blood sugar due to missed meals and a body still recovering from the birth. The result of these factors can be a racing heart, difficulty sleeping even when tired, and a sense of foreboding or dread about what’s to come. The diagnosis of anxiety might be the first and only explanation given when you check in with a doctor, because frankly, it makes sense. With all the information a medical professional is trying to gather in a short visit, it’s unlikely they’ll dig deeper into what your sleep hygiene looks like, how much water you are drinking and how regularly you are eating quality nutrition.

As a new parent, it is entirely plausible that you are experiencing some amount of anxiety. Most parents have concerns about their health, the baby’s health and feel inadequate because they have never had an infant to care for. Bringing home a new baby is stressful, so the healthcare provider is not wrong to pick up on these as symptoms. The picture is just incomplete. The nervous system responds to both worry and depletion with elevated cortisol and adrenaline, activating the stress response. Ignoring physical factors contributing to anxiety leaves parents without the tools they need to feel better.

The physical root causes that mimic anxiety

Sleep debt and a dysregulated stress response

As Sarah's work on the HPA axis explains, sleep gives your body a chance to reset its cortisol levels. New parents face chronic sleep deprivation, keeping cortisol elevated all day and night. This steady stream of stress hormones can manifest as the same jittery, on-edge feeling that you might describe as anxiety. 

Dehydration symptoms that overlap with panic

Many new parents are less focused on their own water intake than making sure the baby is adequately fed. Nursing parents, in particular, often do not get enough water without realizing it. Even mild dehydration can result in an increased heart rate, dizziness, difficulty focusing and a low-grade sense of dread. These are symptoms that can read as panic because they are in fact the same physiological responses of a panic attack.

Blood sugar swings and the racing-heart feeling

Missing meals or grabbing something fast– but not necessarily healthy– is very common in the first days and weeks with a newborn. Blood sugar spikes and then plummets triggering an adrenaline response: racing heart, shakiness, irritability, a sudden wave of worry. It can feel the same as an anxiety spiral, when it’s actually a blood sugar event.

An HPA axis already under load

As Sarah explains through her work with the hypothalamic-pituitary-adrenal (HPA) axis, pregnancy and postpartum recovery already place real demand on this system. The HPA axis governs the body's stress response, and pregnancy and postpartum recovery already place real demand on it. If this stress is combined with lack of sleep, spotty nutrition and dehydration, your body can respond as if threatened even when there is no immediate threat. The perpetual state of activation is how postpartum anxiety actually feels from the inside.

How to tell if it's psychological, physical, or both

In most cases, the root cause of the on-edge feelings are both the physical and psychological stress that new parenthood entails. They amplify each other.  A parent who hasn’t slept well in days or weeks is more reactive to stressful situations. When your mind is stuck chasing down all the “what ifs,” settling down for sleep, and remembering to drink water and eat regularly is much harder. The two feed each other in a loop, which is exactly why addressing only one side often leaves symptoms partially unresolved.

If you’re feeling symptoms of anxiety, here is a useful starting question: when did you last feel this symptom, and had you eaten, drunk, and slept in the hours before? If a clear physical pattern emerges (skipped meals, a bad night, minimal water that day), that's a signal the body is a meaningful part of the picture, even if it isn't the whole picture.

Where to start

It’s helpful for all parents to address their basic physical needs first. It’s much harder to take care of your child when you aren’t taking care of yourself. I start my intake sessions by asking parents about water intake, whether they have good quality nutrition, are taking their vitamins and looking at their sleep hygiene. Then we look for ways to realistically improve each of these, even incrementally. 

Once these basic self care strategies are in place we can address the deeper roots of the feelings and ways to make lasting changes to start this new phase on the best possible footing.

If you want a closer look at how your specific gut, hormone, and stress-response patterns may be playing into this, my colleague Dr. Sarah Khan's Root Cause Quiz is a free starting point.

I've also written “Why am I so anxious”, which takes a look at causes beyond the physical that may be triggering your anxious feelings–and what to do about it.

FAQ

Can dehydration really cause anxiety-like symptoms? Yes. Even mild dehydration can raise heart rate and produce lightheadedness and unease, symptoms that closely resemble a panic or anxiety response.

Is this instead of therapy, or alongside it? Alongside. Addressing physical depletion doesn't replace mental health treatment when anxiety is clinically significant. Taking care of your body is a foundational layer that makes other support more effective.

How is this different from generic self-care advice? This isn't about doing more. It's about identifying specific physiological gaps, sleep, hydration, blood sugar, that are measurably contributing to how anxious the body feels, rather than a general suggestion to sleep when the baby is sleeping.

Why does this get missed so often? Doctor visits are too short and "anxiety" is a faster label than a full look at other causes for the symptoms like lack of sleep, inadequate hydration, and poor nutrition. Neither explanation is wrong. The physical causes are just frequently left out.

Do I need lab testing to know if this applies to me? Not necessarily to start. Noticing whether symptoms line up with missed meals, inadequate sleep, or low fluid intake is a useful first signal. Testing can help pinpoint specifics when the pattern isn't obvious.

Olivia Bergeron, LCSW, PMH-C, is a perinatal psychotherapist and parent coach with over 20 years of clinical experience. She is the founder of Mommy Groove Therapy & Parent Coaching and The Perinatal Connection. If the emotional side of postpartum overwhelm feels familiar, her free Stop/Soften/See guide offers a starting framework for calming the nervous system in the moment.