Headaches most days. A tight neck and shoulders. Thinking that has gone slow, and waking at 4am with the day already running in your head. Sarah searched her symptoms late at night and landed on the worst answer: a brain tumour. Her tests were normal. Then she asked the question this episode is about: "If it's not a tumour, what is it? Because something is wrong with me." In this episode, consultant neurologist Dr Sui Wong explains what running wired can cost you, while the work still gets done and nobody else notices. You'll hear how your two stress systems work, why a stress system that never switches off can leave you exhausted and wide awake at the same time, what that does to memory and sleep, and the honest answer to "Have I already damaged my brain?" In this episode 0:00 Sarah, and the fear she hadn't said out loud 1:44 The cost nobody else sees 3:09 11pm: the only time that belongs to her 4:40 Your two stress systems 5:19 The smoke alarm that never switches off 7:11 Why the day keeps running while you sleep 7:49 Sleep is the brain doing a different job 8:11 Not every headache is stress 8:34 A filing problem, not a memory problem 9:16 Overnight housekeeping, honestly weighed 10:28 Have I already damaged my brain? 12:24 Quick-fire 1: Is stress actually bad for you? 13:38 Quick-fire 2: Does a glass of wine help me sleep? 14:35 Quick-fire 3: Can stress damage your eyesight? 16:11 One small thing: a piece of paper before bed 16:51 When it might be more than stress 17:32 Coming up next Key takeaways Running wired often shows up quietly first: names coming more slowly, small errors in emails, a shorter fuse at home. The work still gets done. It just costs more to produce. Irritability under chronic stress is physiology, not a character flaw. A brain that isn't sleeping properly, on a stress system that never switches off, has less capacity for patience. What looks like a sleep problem is often a stress system still running at night. That is why you can spend eight hours in bed and wake as if you've been at work all night. This is not a one-way door. Sleep, stress hormone rhythm and thinking can improve when conditions change. If you have headaches that worry you, a change in your central vision, or low mood most days, please see your own doctor. Thursday Tips Get my free Thursday Tips: a short weekly newsletter of brain-performance tips, plus a form to send in questions for future episodes: https://brainhealth.fm/ Disclaimers This podcast is for educational purposes only, not medical advice. If something about your health is worrying you, please see your own doctor. Patient stories on Brain Health FM are not real individuals. Each is an amalgamation of the typical patterns Dr Sui Wong sees in clinic, shared in a storytelling way to illustrate what matters for your brain health. References Fries E, et al. (2009). The cortisol awakening response (CAR): facts and future directions. Int J Psychophysiol. DOI: 10.1016/j.ijpsycho.2008.03.014 · PMID: 18854200 Miller GE, et al. (2007). If it goes up, must it come down? Chronic stress and the hypothalamic-pituitary-adrenocortical axis in humans. Psychol Bull. DOI: 10.1037/0033-2909.133.1.25 · PMID: 17201569 Vgontzas AN, et al. (2001). Chronic insomnia is associated with nyctohemeral activation of the hypothalamic-pituitary-adrenal axis: clinical implications. J Clin Endocrinol Metab. DOI: 10.1210/jcem.86.8.7778 · PMID: 11502812 Bonnet MH, Arand DL (1998). Heart rate variability in insomniacs and matched normal sleepers. Psychosom Med. DOI: 10.1097/00006842-199809000-00017 · PMID: 9773766 Perlis ML, et al. (2001). Beta/Gamma EEG activity in patients with primary and secondary insomnia and good sleeper controls. Sleep. DOI: 10.1093/sleep/24.1.110 · PMID: 11204046 Diekelmann S, Born J (2010). The memory function of sleep. Nat Rev Neurosci. DOI: 10.1038/nrn2762 · PMID: 20046194 Deligkaris P, et al. (2014). Job burnout and cognitive functioning: A systematic review. Work & Stress. DOI: 10.1080/02678373.2014.909545 · PMID: not indexed in PubMed Fultz NE, et al. (2019). Coupled electrophysiological, hemodynamic, and cerebrospinal fluid oscillations in human sleep. Science. DOI: 10.1126/science.aax5440 · PMID: 31672896 Shokri-Kojori E, et al. (2018). β-Amyloid accumulation in the human brain after one night of sleep deprivation. Proc Natl Acad Sci U S A. DOI: 10.1073/pnas.1721694115 · PMID: 29632177 Miao A, et al. (2024). Brain clearance is reduced during sleep and anesthesia. Nat Neurosci. DOI: 10.1038/s41593-024-01638-y · PMID: 38741022 Hauglund NL, et al. (2025). Norepinephrine-mediated slow vasomotion drives glymphatic clearance during sleep. Cell. DOI: 10.1016/j.cell.2024.11.027 · PMID: 39788123 McEwen BS, et al. (2016). Stress effects on neuronal structure: hippocampus, amygdala, and prefrontal cortex. Neuropsychopharmacology. DOI: 10.1038/npp.2015.171 · PMID: 26076834 Schmaal L, et al. (2016). Subcortical brain alterations in major depressive disorder: findings from the ENIGMA Major Depressive Disorder working group. Mol Psychiatry. DOI: 10.1038/mp.2015.69 · PMID: 26122586 Echouffo-Tcheugui JB, et al. (2018). Circulating cortisol and cognitive and structural brain measures: The Framingham Heart Study. Neurology. DOI: 10.1212/WNL.0000000000006549 · PMID: 30355700 McEwen BS, Morrison JH (2013). The brain on stress: vulnerability and plasticity of the prefrontal cortex over the life course. Neuron. DOI: 10.1016/j.neuron.2013.06.028 · PMID: 23849196 Ebrahim IO, et al. (2013). Alcohol and sleep I: effects on normal sleep. Alcohol Clin Exp Res. DOI: 10.1111/acer.12006 · PMID: 23347102 Daruich A, et al. (2015). Central serous chorioretinopathy: Recent findings and new physiopathology hypothesis. Prog Retin Eye Res. DOI: 10.1016/j.preteyeres.2015.05.003 · PMID: 26026923 Tsubota K, Nakamori K (1993). Dry eyes and video display terminals. N Engl J Med. DOI: 10.1056/NEJM199302253280817 · PMID: 8426634 Brain Health FM with neurologist Dr Sui Wong Energy, focus and performance: a neurologist's practical guide. New episodes every Tuesday. Free weekly brain-performance tips for consistent energy and focus: join the Thursday Tips newsletter at drwongbrainhealth.com Send in your questions/ topic suggestions: www.BrainHealth.fm Dr Sui Wong is a consultant neurologist and neuro-ophthalmologist who has spent more than 25 years helping tens of thousands of patients. An active clinician-researcher, she also holds qualifications in mindfulness, yoga, movement and lifestyle medicine. She brings what she sees in clinic and what the research shows to the question of how high achievers can get their energy, focus, and clarity back. This podcast is for educational purposes only, not individual medical advice. For concerns about your own health, please speak with your doctor. Stories shared in this podcast do not refer to a specific person (unless stated otherwise with the person's permission), but are a representative amalgamation of the patients or patterns seen in Dr Wong's clinic, shared in a storytelling format for educational purposes only.