Drs Chris and Xand van Tulleken continue their conversation about hydration with Dr John Whittle, a consultant in anaesthesia, critical care and perioperative medicine at University College Hospitals and an honorary associate professor at University College London.

Most of the time our bodies are brilliant at regulating fluid but what happens when that process gets disrupted by illness, stress or ageing? And crucially, what can we do about it?

If you’d like to share your thoughts on this or any other topic covered on the podcast, you email us at [email protected]. Presenters: Drs Chris and Xand van Tulleken Producer and researcher: Dr Samara Linton Executive Producers: Rami Tzabar Editor: Jo Rowntree Visual Producer: Leon Gower Technical Lead: Reuben Huxtable Digital Lead: Richard Berry Composer: Phoebe McFarlane Sound Design: Melvin Rickarby

At the BBC: Assistant Commissioner: Greg Smith Commissioning Editor: Rhian Roberts

A Loftus Media production for BBC Radio 4.

Welcome to What’s Up Docs?, the podcast where doctors and identical twins Chris and Xand van Tulleken explore the ideas shaping our health and wellbeing.

In this episode they’re exploring hydration. We’ve all heard we should be drinking eight glasses of water a day, but does it hold up? Chris and Xand look at what water actually does in the body and how we regulate fluid.

They also separate fact from fiction on the hydration beliefs and trends that are everywhere right now. Does drinking more water actually help you lose weight? What about the online trend of loading water with supplements and flavourings to maximise its benefits? Should we all be adding electrolytes to our water?

To help answer these questions, they’re joined by Dr John Whittle. He’s a consultant in anaesthesia, critical care and perioperative medicine at University College Hospitals and an honorary associate professor at University College London.

If you want to get in touch, you can email us at [email protected]. Presenters: Drs Chris and Xand van Tulleken Producer and researcher: Dr Samara Linton Executive Producers: Rami Tzabar Editor: Jo Rowntree Visual Producer: Leon Gower Technical Lead: Reuben Huxtable Digital Lead: Richard Berry Composer: Phoebe McFarlane Sound Design: Melvin Rickarby

At the BBC:

Assistant Commissioner: Greg Smith Commissioning Editor: Rhian Roberts A Loftus Media production for BBC Radio 4

Chris and Xand van Tulleken continue their conversation with Professor Sunita Sah about why humans follow advice they suspect, or even know, is bad.

They explore what first drew Sunita to this area of research, alongside her own experiences of following advice she knew she should probably question. Together, they unpack the psychology behind why rejecting advice can feel so uncomfortable, and why intelligence or expertise doesn’t necessarily protect people from poor decisions.

If you’d like to share your thoughts on this or any other topic covered on the podcast, please email us at [email protected].

Presenters: Drs Chris and Xand van Tulleken Guest: Professor Sunita Sah Producer: Maia Miller-Lewis Executive Producer: Rami Tzabar Editor: Jo Rowntree Researcher: Grace Revill Tech Lead: Reuben Huxtable Social Media: Leon Gower Visual Producer: Richard Berry Composer: Phoebe McFarlane Sound Design: Ruth Rainey

At the BBC: Assistant Commissioner: Greg Smith Commissioning Editor: Rhian Roberts

A Loftus Media production for BBC Radio 4.

Welcome to What’s Up Docs?, the podcast where doctors and identical twins Chris and Xand van Tulleken explore the ideas shaping our health and wellbeing.

In this episode, they discuss a behaviour almost everyone recognises - following advice we suspect is bad, or even know is wrong. So why do we do it?

From medicine and wellness culture to friendships and everyday life, Chris and Xand unpack the psychology behind why bad advice can be so hard to resist. They consider how authority, confidence and social pressure shape our decisions, and why warning signs don’t always protect us from making choices we later regret. They also ask why questioning experts can feel so difficult, even when our wellbeing depends on it.

Along the way, they discuss how people can become more confident questioning advice, seeking second opinions, and making decisions that genuinely align with their own judgement and wellbeing.

To help them untangle it all, they’re joined by Professor Sunita Sah, Organisational psychologist at Cornell University.

If you want to get in touch, you can email us at [email protected].

Presenters: Drs Chris and Xand van Tulleken Guest: Professor Sunita Sah Producer: Maia Miller-Lewis Executive Producer: Rami Tzabar Editor: Jo Rowntree Researcher: Grace Revill Tech Lead: Reuben Huxtable Social Media: Leon Gower Digital Lead: Richard Berry Composer: Phoebe McFarlane Sound Design: Ruth Rainey

At the BBC: Assistant Commissioner: Greg Smith Commissioning Editor: Rhian Roberts

A Loftus Media production for BBC Radio 4

Chris and Xand continue their conversation about eyes with Mr Raj Das-Bhaumik.

The doctors want to know what particular things we should be doing to look after our eyes in the summer, including how to protect them while swimming or spending time outdoors. They're also curious about dry eye, a common condition that could affect over half of the UK population, and how to manage it, as well as other eye conditions like glaucoma and cataracts and how they are particularly affected in the summer months.

If you’d like to share your thoughts on this or any other topic covered on the podcast, you email us at [email protected].

Presenters: Drs Chris and Xand van Tulleken Guest: Mr Raj Das-Bhaumik Producer: Dr Samara Linton Executive Producer: Rami Tzabar Researcher: Mili Ostojic Tech Lead: Reuben Huxtable Visual Producer: Leon Gower Digital Lead: Richard Berry Composer: Phoebe McFarlane Sound Design: Olga Reed

At the BBC: Assistant Commissioner: Greg Smith Commissioning Editor: Rhian Roberts

A Loftus Media production for BBC Radio 4.

Welcome to What’s Up Docs?, the podcast where identical twin doctors Chris and Xand van Tulleken cut through the confusion around every aspect of our health and wellbeing.

In this episode, Chris and Xand van Tulleken discuss eyes and how to check and protect them. From finding a proper pair of sunglasses to mythbusting common beliefs about eyes, the twins explore the intricacies of an organ that can often be overlooked, especially if you’ve never needed glasses.

To help navigate the maze of online advice, Chris and Xand are joined by Mr Raj Das-Bhaumik, a consultant ophthalmic and oculoplastic surgeon at Moorfields Eye Hospital, one of the world's leading eye hospitals. Together, they break down what everyone needs to look out for when it comes to their eyes.

Presenters: Drs Chris and Xand van Tulleken Guest: Mr Raj Das-Bhaumik Producer: Dr Samara Linton Executive Producer: Rami Tzabar Researcher: Mili Ostojic Tech Lead: Reuben Huxtable Visual Producer: Leon Gower Digital Lead: Richard Berry Composer: Phoebe McFarlane Sound Design: Olga Reed

At the BBC: Assistant Commissioner: Greg Smith Commissioning Editor: Rhian Roberts

A Loftus Media production for BBC Radio 4

Chris and Xand continue their conversation about AI medicine with Dr Emma Karoune.

The docs explore how AI has been used in cutting edge medical research, such as to create digital models of the heart to enable instant alerts to a doctor. They want to know about AI for pattern recognition and how this can be used in determining changes in scans or predicting pandemic. They also want to know more about how ambient AI can be useful to doctors and how data science enables the development of AI technologies.

If you’d like to share your thoughts on this or any other topic covered on the podcast, you email us at [email protected].

Presenters: Drs Chris and Xand van Tulleken Guest: Dr Emma Karoune Producer: Rami Tzabar Executive Producer: Jo Rowntree Assistant Producer: Mili Ostojic Tech Lead: Reuben Huxtable Visual Producer: Leon Gower Digital Lead: Richard Berry Composer: Phoebe McFarlane Sound Design: Olga Reed

At the BBC: Assistant Commissioner: Greg Smith Commissioning Editor: Rhian Roberts

A Loftus Media production for BBC Radio 4.

Welcome to What’s Up Docs?, the podcast where identical twin doctors Chris and Xand van Tulleken cut through the confusion around every aspect of our health and wellbeing.

Can AI empower better self-care and clinical practice, or is it just more health noise? Most of us have fallen down a search engine rabbit hole only to emerge more confused about our symptoms than when we started. But as we enter the era of Large Language Models (LLMs) like ChatGPT, Claude, and Gemini, the landscape of medical information is shifting.

In this episode, Chris and Xand van Tulleken debate whether these AI chatbots, with their vast medical knowledge and surprisingly good "bedside manner", are a breakthrough for patient clarity or a new frontier for misinformation. From asking a chatbot about a "creaky knee" to AI’s burgeoning role in analysing scans, the twins explore a technology that is already transforming GP surgeries and laboratories alike.

While there is plenty to be cautiously excited about, big questions remain. Can we truly trust AI-generated advice? When is it helpful, and when is it dangerous?

To help navigate this rapidly evolving space, Chris and Xand are joined by Dr Emma Karoune, Principal Investigator of the Clinical AI Interest Group and Advancing Biomedical Data Science Careers project at The Alan Turing Institute. Together, they break down what patients and practitioners need to look out for in the age of AI medicine.

If you’d like to share your thoughts on this or any other topic covered on the podcast, you email us at [email protected].

Presenters: Drs Chris and Xand van Tulleken Guest: Dr Emma Karoune Producer: Rami Tzabar Executive Producer: Jo Rowntree Assistant Producer: Mili Ostojic Tech Lead: Reuben Huxtable Visual Producer: Leon Gower Digital Lead: Richard Berry Composer: Phoebe McFarlane Sound Design: Olga Reed

At the BBC: Assistant Commissioner: Greg Smith Commissioning Editor: Rhian Roberts

A Loftus Media production for BBC Radio 4

In this extended episode of What's Up Docs?, Chris and Xand van Tulleken continue their conversation with Professor Robin Condliffe.

Together, they explore how our understanding of the lungs has evolved over time, from early theories about breathing to the breakthroughs that transformed modern respiratory medicine.

They also examine why lung health is shaped by more than biology alone. From air pollution and housing quality to poverty and access to healthcare, they discuss the social and environmental factors that continue to influence who develops lung disease and who receives treatment.

Recording at Crossed Wires Festival in Sheffield, they reflect on the city's industrial heritage and the lessons it offers for modern public health. They also ask what has changed in respiratory medicine during Robin's career, and how his work has influenced the way he thinks about his own health and wellbeing.

If you’d like to share your thoughts on this or any other topic covered on the podcast, you can email us at [email protected].

Presenters: Drs Chris and Xand van Tulleken Guest: Professor Robin Condliffe Producer: Maia Miller-Lewis Editor: Jo Rowntree Executive Producer: Rami Tzabar Researcher: Grace Revill Production Manager: Lisa Lipman Tech Lead: Reuben Huxtable Social Media: Leon Gower Digital Lead: Richard Berry Composer: Phoebe McFarlane Sound Design: Melvin Rickarby

At the BBC: Assistant Commissioner: Greg Smith Commissioning Editor: Rhian Roberts

A Loftus Media production for BBC Radio 4.

Welcome to What's Up Docs?, the podcast where doctors and identical twins Chris and Xand van Tulleken explore the ideas shaping our health and wellbeing.

In this episode, recorded live at Crossed Wires Festival in Sheffield, they are joined by Professor Robin Condliffe, Consultant Respiratory Physician at Royal Hallamshire Hospital.

Together, they explore the extraordinary science of the lungs: how they work, how they keep us alive, and what happens when they start to go wrong. From asthma, COPD and lung cancer to air pollution, smoking and respiratory infections, they discuss some of the biggest challenges facing lung health today.

Along the way, they examine the links between lung health, deprivation and the environment, reflect on Sheffield's industrial heritage, and explore the latest advances in respiratory medicine. Finally, they ask what we can all do to keep our lungs healthier for longer. If you want to get in touch, you can email us at [email protected].

Presenters: Drs Chris and Xand van Tulleken Guest: Professor Robin Condliffe Producer: Maia Miller-Lewis Editor: Jo Rowntree Executive Producer: Rami Tzabar Researcher: Grace Revill Production Manager: Lisa Lipman Tech Lead: Reuben Huxtable Social Media: Leon Gower Digital Lead: Richard Berry Composer: Phoebe McFarlane Sound Design: Melvin Rickarby

At the BBC: Assistant Commissioner: Greg Smith Commissioning Editor: Rhian Roberts

A Loftus Media production for BBC Radio 4

Chris and Xand van Tulleken take a deeper dive into heart palpitations and the rise of wearable technology.

With devices like smartwatches now able to detect irregular heart rhythms, more people are being alerted to potential problems, often without any symptoms. But is this early detection saving lives, or creating new challenges?

Joined again by Consultant Cardiologist Dr Pranev Sharma, the docs explore how wearables actually work, how accurate they are, and what happens when they flag something abnormal. They unpack the balance between prevention and overdiagnosis, and ask whether we risk medicalising normal bodily sensations. They also look at how decisions are made about treatment, and whether these decisions are changing as more cases are detected through technology.

If you’d like to share your thoughts on this or any other topic covered on the podcast, you email us at [email protected] or Whatsapp on 08000 665 123.

Presenters: Drs Chris and Xand van Tulleken Guest: Dr Pranev Sharma Producer: Maia Miller-Lewis Executive Producer: Rami Tzabar Editor: Kirsten Lass Researcher: Grace Revill Tech Lead: Reuben Huxtable Visual Producer : Leon Gower Digital Lead: Richard Berry Composer: Phoebe McFarlane Sound Design: Olga Reed

At the BBC: Assistant Commissioner: Greg Smith Commissioning Editor: Rhian Roberts

A Loftus Media production for BBC Radio 4.