Dehydration causes headaches, loss of concentration and tiredness (not necessarily in that order).
Sitting and staring at your desk for hours on end also causes loss of concentration, tiredness and sore muscles.
Here's a solution to both: make a point of refilling your glass with a water-based drink every hour or so; go to the furthest kitchen/water cooler that makes sense; and take a different path every time. Set a reminder if you need to.
You'll drink enough to remain hydrated, you'll get gentle exercise for your legs and back, and bonus: you'll meet other teams on your way and you'll share the water cooler with people you wouldn't talk to otherwise.
Extending your company-network outside of the people who you work with on a daily basis will give you more visibility and more expertise to pick from when you need advice.
Do it at regular times and see if you can get people to expect you. Stop and talk briefly to those you walk past if you notice anything interesting on their desk or screens - you don’t have to engage in long conversations, just introduce yourself and say a quick sentence and if they want to talk to you longer they'll show it.
What is shared around your nearest water cooler is curated and formatted to suit the regulars; talking to people who don't expect you is spontaneous and yields more interesting information and relationships.
This site does not provide medical advice, professional diagnosis, opinion, treatment or services. This site provides general information for educational purposes only. The information provided in this site is not a substitute for medical or professional care. If you are concerned about your health problem you should consult your physician or other healthcare provider.