Are You Secretly Dehydrated? Why a 1% Drop Kills Your Focus and Mood

Heart Rate Variability | Why Your Nervous System Needs This.

We all experience stress. The real challenge isn't stress itself—it's whether we recover from it. Over time, chronic stress can quietly affect everything from inflammation and metabolism to sleep, digestion, and healthy aging. This week on The Dr. Hyman Show, I talk with nervous system educator and HRV expert Salim Najjar to explore what heart rate variability (HRV) can reveal about your body's ability to recover from stress and build resilience. Together, we unpack: • How to use HRV to better understand your body's response to stress • Why some stress makes you stronger while chronic stress wears you down • How to get more value from your wearable without obsessing over the numbers • Five daily habits that can help your nervous system recover and become more resilient • How your nervous system influences inflammation, healing, and healthy aging Our bodies are constantly responding to the demands we place on them every day. The good news is that resilience can be built, and the strategies in this conversation can help you recover from stress more effectively and support long-term health. To help you get started, Salim has created a free HRV guide [https://thathrvguy.com/hyman] that includes a personalized quiz and AI coach exclusively for listeners.View Show Notes From This Episode [https://drhyman.com/blogs/content/podcast-ep1160]Sign up for Dr. Hyman’s Brainshaping Academy to learn how to nourish the biological systems that support your mental, emotional, and cognitive health https://drhyman.com/products/brainshaping?utm_source=dr_hyman_show&utm_medium=newsletter&utm_campaign=may_27&utm_content=link [https://drhyman.com/products/brainshaping?utm_source=dr_hyman_show&utm_medium=newsletter&utm_campaign=may_27&utm_content=link]Get Free Weekly Health Tips from Dr. Hyman [https://drhyman.com/picks/?utm_source=podcast&utm_medium=banner&utm_campaign=shownotes]https://drhyman.com/pages/picks?utm_campaign=shownotes&utm_medium=banner&utm_source=podcast [https://drhyman.com/pages/picks?utm_campaign=shownotes&utm_medium=banner&utm_source=podcast]Sign Up for Dr. Hyman’s Weekly Longevity Journal [https://drhyman.com/longevity/?utm_source=podcast&utm_medium=banner&utm_campaign=shownotes]https://drhyman.com/pages/longevity?utm_campaign=shownotes&utm_medium=banner&utm_source=podcast [https://drhyman.com/pages/longevity?utm_campaign=shownotes&utm_medium=banner&utm_source=podcast]Join the 10-Day Detox to Reset Your Health [https://drhyman.com/pages/10-day-detox]https://drhyman.com/pages/10-day-detox [https://drhyman.com/pages/10-day-detox]Join the Hyman Hive for Expert Support and Real Results [https://drhyman.com/pages/hyman-hive]https://drhyman.com/pages/hyman-hive [https://drhyman.com/pages/hyman-hive] This episode is brought to you by Perfect Amino, Cozy Earth, Timeline, Sunlighten, Made In, and Seatopia. Get daily protein support at bodyhealth.com [http://bodyhealth.com/] and use code HYMAN20 for 20% off. Head over to cozyearth.com [http://cozyearth.com/] to save 20% and upgrade all of your daily essentials today. Support healthy aging and get 20% at timeline.com/drhyman [http://timeline.com/drhyman] with code HYMAN. Discover why so many people are using sunlighten.com [http://sunlighten.com/] and use code HYMAN to save up to $2,100 today with free shipping. Upgrade your cookware at madeincookware.com [http://madeincookware.com/] and save 10% off your first order with code HYMAN-HIVE. Find a cleaner source of seafood. Check out seatopia.fish [https://seatopia.fish/] and receive free shipping on your first order. (0:00) Introduction to HRV (3:43) Introduction to Salim and his HRV expertise (4:18) What is HRV and how is it measured (5:32) Chronic stress, stress regulation, and sovereignty (9:52) Why HRV is an important health metric (20:31) Deeper dive into HRV as a health indicator (25:43) Salim's HRV coaching, website, and personal journey (28:49) Salim’s framework and steps for improving HRV (30:07) The role of sleep and hormetic stress in HRV (33:12) Tools and tracking for HRV measurement (37:22) The art framework and five pathways for HRV (38:17) Salim’s injury, reframing, and HRV improvement (46:22) Viktor Frankl, intentionality, and alignment (51:46) Community and its role in health and HRV (55:02) Practical steps for building community and emotional regulation (58:18) Emotional processing, elite athletes, and HRV performance (1:00:35) Sovereignty, compassion, and daily nervous system practices (1:03:18) Awareness, parasympathetic activation, and reframing HRV (1:05:01) Closing remarks, social media, and gratitude (1:05:51) Disclaimer and sponsor acknowledgments

Too Much Histamine Is Wrecking Your Body — And Most Doctors Don't Know It

Histamine isn't just about seasonal allergies or a runny nose. It influences your brain, gut, hormones, immune system, and nervous system—and when your body can't regulate it properly, it can show up as everything from anxiety and migraines to insomnia, digestive issues, skin rashes, and brain fog. In this episode, I explain why histamine overload happens, how it relates to Mast Cell Activation Syndrome (MCAS), and what a root-cause approach looks like for calming an overactive immune system. In today's episode, I discuss: * Why MCAS and histamine intolerance are different—and how overactive mast cells can drive symptoms ranging from migraines and anxiety to digestive issues, hives, and heart palpitations * The hidden triggers behind mast cell activation, including gut dysfunction, chronic infections, mold exposure, hormone imbalances, stress, and environmental toxins * Why many "healthy" foods like avocados, spinach, tomatoes, kombucha, and bone broth can temporarily worsen symptoms when your histamine bucket is already full * A root-cause approach to calming the immune system using nutrition, targeted supplements, medications when needed, nervous system regulation, and addressing the underlying drivers of inflammation MCAS isn't simply a histamine problem—it's a sign that your immune system has become dysregulated. Instead of just suppressing symptoms, the goal is to understand why your mast cells are overreacting in the first place. When you lower the overall inflammatory load and restore balance to the gut, immune system, hormones, and nervous system, you create the conditions for lasting healing rather than temporary symptom relief. Resources Mentioned: * Track your biomarkers with Function Health: https://functionhealth.com/mark [https://functionhealth.com/mark] (Use code MARK2026 for $50 off your membership.) * Have a question you’d love answered on Office Hours? Submit it here [https://docs.google.com/forms/d/e/1FAIpQLSdNF2y4lFWEOMLlzVNlFDpJ4xl7oOpH9NlImMoHr5mHggL_Ww/viewform?usp=header]

How Brain Inflammation Drives Depression, Alzheimer's, and Parkinson's

For decades, we've thought about conditions like Alzheimer's disease, depression, and Parkinson's disease as disorders of the brain. But what if that's only part of the story? Emerging science is revealing that many of the factors driving cognitive decline, mental illness, and neurodegenerative disease may begin far outside the brain itself—in our metabolism, our immune system, our gut microbiome, our hormones, and even the environment we're exposed to every day. As part of our summer series, we're revisiting some of the most important conversations we've had on the topic of brain health. In this special compilation episode, you'll hear from leading experts Dr. Richard Isaacson, Dr. Chris Palmer, and Drs. Ray Dorsey and Michael Okun as they explore the new science of brain health and what it means for preventing cognitive decline, supporting mental health, and protecting our brains as we age. What I find most encouraging about this research is that it challenges the idea that brain decline is simply an inevitable part of aging. Instead, it suggests that many of the biggest drivers of brain health are things we can influence through the choices we make, the environments we create, and the ways we care for our bodies long before symptoms ever appear. View Show Notes From This Episode [https://drhyman.com/blogs/content/podcast-ep1158]Sign up for Dr. Hyman’s Brainshaping Academy to learn how to nourish the biological systems that support your mental, emotional, and cognitive health [https://drhyman.com/products/brainshaping?utm_source=dr_hyman_show&utm_medium=newsletter&utm_campaign=may_27&utm_content=link] https://drhyman.com/products/brainshaping?utm_source=dr_hyman_show&utm_medium=newsletter&utm_campaign=may_27&utm_content=link [https://drhyman.com/products/brainshaping?utm_source=dr_hyman_show&utm_medium=newsletter&utm_campaign=may_27&utm_content=link] Get Free Weekly Health Tips from Dr. Hyman [https://drhyman.com/picks/?utm_source=podcast&utm_medium=banner&utm_campaign=shownotes] https://drhyman.com/pages/picks?utm_campaign=shownotes&utm_medium=banner&utm_source=podcast [https://drhyman.com/pages/picks?utm_campaign=shownotes&utm_medium=banner&utm_source=podcast] Sign Up for Dr. Hyman’s Weekly Longevity Journal [https://drhyman.com/longevity/?utm_source=podcast&utm_medium=banner&utm_campaign=shownotes] https://drhyman.com/pages/longevity?utm_campaign=shownotes&utm_medium=banner&utm_source=podcast [https://drhyman.com/pages/longevity?utm_campaign=shownotes&utm_medium=banner&utm_source=podcast] Join the 10-Day Detox to Reset Your Health [https://drhyman.com/pages/10-day-detox] https://drhyman.com/pages/10-day-detox [https://drhyman.com/pages/10-day-detox] Join the Hyman Hive for Expert Support and Real Results [https://drhyman.com/pages/hyman-hive] https://drhyman.com/pages/hyman-hive [https://drhyman.com/pages/hyman-hive] This episode is brought to you by Timeline, Sunlighten, Seed, BIOptimzers, Paleovalley, and Pique. Support healthy aging and get 20% off at timeline.com/drhyman [http://timeline.com/drhyman] with code HYMAN. Discover why so many people are using sunlighten.com [http://sunlighten.com/] and save up to $2,100 today and free shipping with code HYMAN. Make your microbiome part of your daily routine with seed.com/hyman [http://seed.com/hyman] and save 25% with code 25HYMAN. Go to bioptimizers.com/hyman [http://bioptimizers.com/hyman] and use code HYMAN to save 15% off your order, plus get a free gift.  Shop nutrient-rich foods and supplements at paleovalley.com/hyman [http://paleovalley.com/hyman] and save 15% off your first order. Elevate your daily wellness ritual at piquelife.com/hyman [http://piquelife.com/hyman] and enjoy 15% off for life plus free gift (0:00) Understanding brain dysfunction, inflammation, and lifestyle interventions (0:21) Heavy metals, toxins, and Parkinson's disease (3:30) Introduction to the summer series on brain health (4:02) The MIND diet, precision nutrition, and brain-healthy fats (9:06) Vitamins, supplements, and caloric intake for cognitive health (11:23) Vitamin D, B complex, and reversing mild cognitive impairment (14:05) Additional supplements and intensive lifestyle interventions (17:18) Importance of magnesium and metabolic health (18:24) Multimodal treatments, hormone replacement therapy, and individualized care (26:49) Biopsychosocial factors, stress, and the gut-brain connection (32:30) Inflammation, energy dysregulation, and metabolism in brain health (42:33) Parkinson's disease: causes, history, and environmental factors (46:02) Leaky brain, blood-brain barrier, and Parkinson's as a whole-body disease (49:00) Closing remarks, disclaimer, and gratitude to sponsors

Encore: Your Nervous System Controls Your Gut, Hormones, and Weight — Here's How to Fix It

You've cleaned up your diet. You're taking the supplements. You're exercising, sleeping more, and doing everything "right." So why do you still feel exhausted, inflamed, anxious, or stuck? In this encore episode—one of the most impactful Office Hours conversations we've shared—I explore a question that could change the way you think about healing: What if your nervous system is the missing piece? When your body doesn't feel safe, it prioritizes survival over repair, affecting everything from your metabolism and hormones to your gut, immune system, and brain. In today's episode, I break down: * Why chronic stress changes your biology—and how nervous system dysregulation can drive inflammation, hormone imbalance, digestive issues, weight gain, and autoimmune disease * The difference between living in constant "fight-or-flight" versus a regulated nervous system that supports healing, resilience, and recovery * Simple, science-backed strategies to regulate your nervous system, including breathwork, blood sugar balance, strength training, sleep, and daily safety cues * Why you can't out-supplement or out-biohack chronic stress—and how creating physiological safety unlocks your body's natural ability to heal Healing isn't just about finding the right supplement or following the perfect diet. It's about creating an environment where your body feels safe enough to repair itself. When you begin working with your nervous system instead of against it, everything else—from your energy and metabolism to your mood and resilience—can start to change. Check out my full conversation with Dr. Scott Sherr HERE [https://drhyman.com/blogs/content/podcast-ep1133]. Track your health with Function Health: https://functionhealth.com/mark [https://functionhealth.com/mark] (Use code MARK2026 for $50 off your membership.) Have a question you’d love answered on Office Hours? Submit it here [https://docs.google.com/forms/d/e/1FAIpQLSdNF2y4lFWEOMLlzVNlFDpJ4xl7oOpH9NlImMoHr5mHggL_Ww/viewform?usp=header] Resources Mentioned: * Listen to my full conversation [https://drhyman.com/blogs/content/podcast-ep1133] with Dr. Scott Sherr on nervous system regulation and mitochondrial health.

3 Heart Experts Reveal What Really Prevents Heart Disease

As part of our summer series, we're revisiting some of the most important conversations we've had on the topics that matter most to our health. And few are more important than heart disease. Heart disease remains the number one cause of death worldwide. Yet despite decades of research, millions of prescriptions, and billions of dollars spent on treatment, many people are still confused about what actually causes it—and what we can do to prevent it. For years, the conversation around heart disease has focused almost entirely on cholesterol. But what if that's only part of the story? In this special compilation episode, you'll hear from Dr. Cindy Geyer of The UltraWellness Center [https://www.ultrawellnesscenter.com/], Dr. Eric Topol, and Dr. Aseem Malhotra as they explore a different perspective on heart disease—one that goes beyond cholesterol and looks at the deeper drivers of cardiovascular risk, including inflammation, insulin resistance, metabolic dysfunction, lifestyle, and early detection. You'll hear why many experts now believe heart disease often begins decades before symptoms appear, why traditional testing can miss important warning signs, and how emerging science is giving us new tools to identify risk earlier than ever before. Most importantly, you'll hear a message that is both practical and hopeful: that many of the factors driving heart disease are within our control, and that prevention remains one of the most powerful tools we have. Let's dive in. View Show Notes From This Episode [https://drhyman.com/blogs/content/podcast-ep1155]Sign up for Dr. Hyman’s Brainshaping Academy to learn how to nourish the biological systems that support your mental, emotional, and cognitive health [https://drhyman.com/products/brainshaping?utm_source=dr_hyman_show&utm_medium=newsletter&utm_campaign=may_27&utm_content=link] https://drhyman.com/products/brainshaping?utm_source=dr_hyman_show&utm_medium=newsletter&utm_campaign=may_27&utm_content=link [https://drhyman.com/products/brainshaping?utm_source=dr_hyman_show&utm_medium=newsletter&utm_campaign=may_27&utm_content=link] Get Free Weekly Health Tips from Dr. Hyman [https://drhyman.com/picks/?utm_source=podcast&utm_medium=banner&utm_campaign=shownotes] https://drhyman.com/pages/picks?utm_campaign=shownotes&utm_medium=banner&utm_source=podcast [https://drhyman.com/pages/picks?utm_campaign=shownotes&utm_medium=banner&utm_source=podcast] Sign Up for Dr. Hyman’s Weekly Longevity Journal [https://drhyman.com/longevity/?utm_source=podcast&utm_medium=banner&utm_campaign=shownotes] https://drhyman.com/pages/longevity?utm_campaign=shownotes&utm_medium=banner&utm_source=podcast [https://drhyman.com/pages/longevity?utm_campaign=shownotes&utm_medium=banner&utm_source=podcast] Join the 10-Day Detox to Reset Your Health [https://drhyman.com/pages/10-day-detox] https://drhyman.com/pages/10-day-detox [https://drhyman.com/pages/10-day-detox] Join the Hyman Hive for Expert Support and Real Results [https://drhyman.com/pages/hyman-hive] https://drhyman.com/pages/hyman-hive [https://drhyman.com/pages/hyman-hive] This episode is brought to you by BON CHARGE, BIOptimizers, Rho, Made In, Seatopia, and Cozy Earth. Explore red light products at boncharge.com/hyman [http://boncharge.com/hyman] and enjoy 15% off with code HYMAN. Go to bioptimizers.com/hyman [http://bioptimizers.com/hyman] and use code HYMAN to save 15% off your order, plus get a free gift.  Explore science-backed products at rhonutrition.com [http://rhonutrition.com/] and use code HYMAN for 20% off the entire site. Upgrade your cookware at madeincookware.com [http://madeincookware.com/] and save 10% off your first order with code HYMAN-HIVE. Find a cleaner source of seafood. Check out seatopia.fish/hyman [http://seatopia.fish/hyman] and receive free shipping on your first order. Head to cozyearth.com [http://cozyearth.com/] to save 20% and upgrade all of your daily essentials today. (0:00) The persistence of heart disease and the low-fat diet hypothesis (0:32) Preventing heart disease through diet, lifestyle, and simple behaviors (2:19) Revisiting key conversations on heart disease (3:44) Beyond cholesterol: deeper drivers and risk factors (7:18) Typical workup, treatments, and advances in cholesterol testing (17:48) Metabolic health, hormonal, and inflammatory factors in heart disease (29:37) Advances in cardiovascular diagnostics and AI (31:31) Impact of lifestyle and new pharmacological treatments (36:55) Statins, side effects, and lipoprotein fractionation (40:13) The role of AI, new diagnostics, and Dr. Topol's journey (43:19) Rethinking treatment: diet, industry influence, and the low-fat craze (45:28) Saturated fat, cholesterol, and revisiting the evidence (48:00) Cholesterol in heart disease risk and systematic drug review (52:31) Insulin resistance, cholesterol’s role, and mortality (58:31) Challenges in changing medical dogma (1:00:31) Closing remarks and call to action