Stress in the Body: How Ayurveda Reads Nervous Depletion

Author: Swastik Research Desk

TL;DR

Acute stress activates the sympathetic nervous system and the HPA axis: heart rate, breathing, and blood pressure rise while cortisol mobilizes energy. Chronic stress is associated with increased HPA-axis activity and a range of health problems. Ayurveda traditionally reads chronic stress as depleting ojas.

What happens in the body during acute stress?

The acute stress response — the fight-or-flight reaction — involves increased heart rate, breathing rate, and blood pressure, together with tensed muscles and increased sweating (NCCIH).

This response has two arms. The fast arm is the sympathetic nervous system, driven by adrenaline, acting in seconds to prepare the body for action (NCCIH).

The slower arm is hormonal: stressors stimulate the hypothalamus to release CRH (corticotropin-releasing hormone), which prompts the pituitary to release ACTH, which in turn drives the adrenal cortex to release cortisol (Chan & Debono, PMC).

Cortisol then mobilizes energy and feeds back on the hypothalamus and pituitary to shut the response down — a negative-feedback loop when it works properly (Chan & Debono, PMC).

Occasional stress is a normal part of coping; NCCIH notes that long-term stress is associated with a range of health problems (NCCIH).

What is the HPA axis?

HPA stands for hypothalamus–pituitary–adrenal: the hormonal chain described above, from brain to adrenal gland and back (Chan & Debono, PMC).

The axis is under circadian control from the brain's master clock (the suprachiasmatic nucleus), which is why cortisol follows a daily rhythm: low around midnight, beginning to rise around 2:00–3:00 AM, and peaking near 8:30 AM in healthy adults (Chan & Debono, PMC).

The same review distinguishes the circadian overnight rise from the stress response: they share the same hormone but are regulated differently (Chan & Debono, PMC).

In chronic stress, the picture changes: endocrinology reviews list chronic stress among the conditions with increased activity of the HPA axis (Chrousos, 2009).

The HPA axis is therefore not a "stress switch" but a regulated system — one that can be pushed into a higher gear for long periods.

How does chronic stress differ from acute stress?

Acute stress is a sprint; chronic stress is a state. Long-term stress may contribute to or worsen digestive disorders, headaches, sleep disorders, and asthma, according to NCCIH (NCCIH).

It is also linked to depression and anxiety — mood disorders in which stress physiology and mental health reinforce each other (NCCIH).

Endocrinology reviews associate chronic stress with a cluster of manifestations — anxiety, depression, cognitive dysfunction, hypertension, metabolic disorders, and sleep disorders — while stressing that these are associations in complex systems, not simple cause and effect (Chrousos, 2009).

The honest summary: stress is a contributor that interacts with genetics, sleep, diet, and circumstance — never a sole cause, and never a diagnosis you can make from a symptom list.

How does Ayurveda traditionally read chronic stress in the body?

Ayurveda reads the body through a different vocabulary. In the traditional view, chronic mental stress is one of the primary factors that depletes ojas — the vital essence described as the body's reserve of vitality, resilience, and resistance to disease (Prabhakar, IRJAY 2025).

The same review describes stress as disrupting the nervous system and increasing stress hormones such as cortisol — an interesting parallel with modern physiology, though the frameworks remain distinct (Prabhakar, IRJAY 2025).

Chronic sleep deprivation is likewise said to weaken immunity and deplete ojas, linking the traditional view of stress, sleep, and resilience into one picture (Prabhakar, IRJAY 2025).

Ojas is a traditional concept, not a measurable substance: it should not be equated with cortisol, melatonin, or immunity as biomedicine defines them.

For the dosha side of this reading — how aggravated Vata maps onto nervous-system overactivity — see Vata dosha, and for the digestion connection see agni and digestion.

What does the evidence say about calming the stress response?

The most established counter-move is the relaxation response: NCCIH describes it as producing the opposite physiological effects of the stress response — slower heart rate, lower blood pressure, decreased oxygen consumption and stress hormones (NCCIH).

Mindfulness meditation has modest backing: a 2019 review of 18 studies found it may reduce stress and anxiety and improve sleep quality, per NCCIH's summary (NCCIH).

Slow, deep breathing may modestly lower blood pressure and cortisol — a small effect, and generally a safe practice, though NCCIH notes relaxation techniques can occasionally cause anxiety or intrusive thoughts in some people (NCCIH).

Yoga shows a similar pattern: some studies find improvements in stress-related outcomes, but not all do — and NCCIH is explicit about the limitations in this literature (NCCIH).

The pattern across these is honest but modest: small effects in the studies we have, mixed evidence in places — not cures, but levers.

What about ashwagandha for stress?

The strongest single trial is a 2012 randomized, double-blind, placebo-controlled study (RCT) that enrolled 64 adults with chronic stress, 61 of whom completed the protocol (Chandrasekhar et al., 2012).

Participants took 300 mg of KSM-66 ashwagandha root extract — standardized to at least 5% withanolides — twice daily for 60 days, and showed significant reductions in all stress-assessment scores (P < 0.0001) plus reduced serum cortisol versus placebo (Chandrasekhar et al., 2012).

Adverse effects were mild and comparable with placebo — but this was a single-center trial of one branded extract, and results do not automatically generalize (Chandrasekhar et al., 2012).

A 2022 meta-analysis of 12 RCTs (1,002 participants) found pooled reductions in stress and anxiety — but rated the certainty of evidence low for both outcomes, noted high heterogeneity, and called for more high-quality trials (Akhgarjand et al., 2022).

NCCIH's framing is the most cautious: some ashwagandha preparations may be effective for stress, evidence for anxiety is unclear, short-term use up to three months may be safe, and long-term safety is unknown (NCCIH).

Trial doses describe research regimens, not recommendations — consult a qualified practitioner. For the full evidence picture, see ashwagandha.

Practical takeaways

• Acute stress is two systems: fast sympathetic activation and the slower HPA-axis cortisol cascade.
• Cortisol runs on a clock — lowest near midnight, rising from 2:00–3:00 AM — which is normal, not pathological.
• Chronic stress is a contributor to digestive, sleep, headache, and mood problems, never a sole cause.
• Slow breathing, mindfulness, and the relaxation response have modest, honest evidence behind them.
• Ashwagandha's stress evidence is low-certainty; treat it as an open question, not an answer.

FAQs

Is stress really making me sick?

Stress is a contributor, not a sole cause. NCCIH states that long-term stress may contribute to or worsen digestive disorders, headaches, sleep disorders, and asthma, and is linked to depression and anxiety (NCCIH). Chronic stress is also associated with increased HPA-axis activity (Chrousos, 2009). Managing stress is worthwhile, but persistent symptoms deserve medical evaluation, not self-diagnosis.

How is cortisol different from adrenaline?

They are the two arms of the stress response. The sympathetic arm — adrenaline — acts in seconds: heart rate, breathing rate, and blood pressure rise, muscles tense (NCCIH). The HPA axis is slower: the hypothalamus releases CRH, the pituitary releases ACTH, and the adrenal cortex releases cortisol over minutes, which then feeds back to shut the system down (Chan & Debono, PMC).

Does meditation really lower stress hormones?

There is modest evidence. NCCIH summarizes a 2019 review of 18 studies finding mindfulness meditation may improve sleep quality, and notes slow deep breathing may modestly lower blood pressure and cortisol (NCCIH). The relaxation response produces physiological effects opposite to the stress response. But NCCIH also flags limitations in this research — promising, not proven.

Can ashwagandha fix my stress?

No herb "fixes" stress. In a 60-day RCT that enrolled 64 chronically stressed adults (61 completed), 300 mg of KSM-66 ashwagandha twice daily reduced stress scores and serum cortisol versus placebo (Chandrasekhar et al., 2012). But a meta-analysis of 12 RCTs rated the pooled evidence low-certainty with high heterogeneity (Akhgarjand et al., 2022), and NCCIH says anxiety evidence is unclear and long-term safety unknown (NCCIH).

What does Ayurveda mean by ojas and stress?

In the traditional Ayurvedic view, ojas is the vital essence — the body's reserve of vitality and resilience — and chronic mental stress is described as one of the primary factors that depletes it, disrupting the nervous system and weakening immunity (Prabhakar, IRJAY 2025). This is a traditional concept, not a measurable substance; do not equate ojas with cortisol, melatonin, or immunity as biomedicine defines them.

Sources

• NCCIH — Stress and mind-body practices
• Chan & Debono — Stress, circadian regulation, cortisol (PMC)
• Chrousos 2009 — Stress and disorders of the stress system (Nature Reviews Endocrinology)
• Prabhakar 2025 — Ojas: an Ayurvedic concept of immunity (IRJAY)
• Chandrasekhar et al. 2012 — Ashwagandha stress RCT (PMC)
• Akhgarjand et al. 2022 — Ashwagandha stress meta-analysis (Phytotherapy Research)
• NCCIH — Ashwagandha

Disclaimer

This guide is educational and is not medical advice. It does not diagnose, treat, or prevent any condition, and it does not replace consultation with a qualified health practitioner or, where Ayurveda is concerned, a qualified Ayurvedic practitioner. If stress symptoms persist or affect your daily life, seek medical advice.