Purpose: This page is a place for you to post any questions you want about physiology and also a place where you can answer questions from others. I will try to pay attention to what is posted, do some research, and give answers, but feel free to jump right in and help out too. To keep this page from getting messy, I will move questions and answers to the Past Questions page soon after they are answered.

• What happens physiologically when a person "drinks to death" with only water? Does it relate to potassium levels?
• I haven't researched this yet, but I'm going to introduce a couple of terms: hyponatremia is low sodium, while hypokalemia is low potassium (and hypernatremia and hyperkalemia are too high levels of each). Marathon runners who drink lots of water during the race, but just water (not Gatorade or other electrolyte solutions) often end up with hyponatremia. It's a race to see who figures out this question! ~K
• I still don't know much about it, but I have heard it termed water intoxication. When you drink too much water (i.e., at rest, more than 1.5L/hr), your body cannot rid itself of the liquid at the same rate you are ingesting it. It then dilutes the concentration of electrolytes in your blood, resulting in hyponatremia and/or hypokalemia, of which the latter is most common. If you are exercising, your body is losing more water and is thus able to intake more. Here is the Wikipedia article.
  


• I have VonWillebrand's Disease type 2N. This disease causes a lack of VonWillebrand protein, which is a clotting factor in the blood. It is also the carrier for factor 8, which plays a role in Hemophilia. As part of treatment for VwD, I am given a large dose of ADH (Antidiuretic hormone). In addition to a myriad of unpleasant side effects, it raises my natural level of clotting factors in my blood. Why is this?
• Ooh. . . this is a great question! I have never heard of ADH being given to increase blood clotting factors! Does it make you terribly thirsty? Do you have problems with edema from your kidneys not releasing enough fluids? How about high blood pressure? The possible side effects are intriguing. I'll be curious to read what people find on this (or to research it myself eventually). ~K
• Well, I am not allowed to drink more than about 8 oz in a 12 hour period, because it shuts my kidneys down. Somehow I don't think the message gets to my brain though, because I'm very thirsty. I also get very drowsy and balloon up like one of those balloon animals. I actually tend to have a high BP at the initiation of the meds, but my BP drops rapidly afterward. It usually takes a good 48 hours for the symptoms to reside after the initial dose. I haven't been able to figure out the link so far...I hope someone else can! ~E
  

• We know what too little iron in the blood causes.. Anemia. What does too much iron cause?
• Almost all of the iron is recovered and reused when red blood cells are broken down, so your daily dietary needs of iron are actually quite low. The main reason women suffer from iron-deficient anemia more than men is that they menstruate--while in general this also makes them less likely to have too much iron, many women take iron supplements soboth men and women can suffer from hemochromatosis. People with a particular allele of a gene are much more likely to have hemochromatosis--and this allele is more common in people of European descent (especiallyfrom the British Isles)--so this is actually considered a hereditary disease (even though most people with the gene don't get disease symptoms). Hemochromatosis may take years (decades) to develop as the body slowly accumulates too much iron in the liver and other tissues (such as the pancreas and heart), eventually damaging those organs. Symptoms are quite vague in the early stages--fatigue, joint pain, weight loss, abdominal pain. . . in later stages a whole variety of symptoms may present as organs are damaged (such as liver cirrhosis, diabetes, and more. See here for a larger list). Diagnosis is through a fasting blood test for transferrin saturation and serum ferritin (these are proteins that bind to free iron in the blood). These are not part of a routine blood test, but are easy to do. There are other things involved in diagnosis, as mentioned in this Wikipedia article. Treatment is therapeutic phlebotomy where they remove a unit of blood every week or two until iron levels return to normal (and then continue to remove a unit of blood 3 or 4 times yearly after that. I guess it's a good argument for why you should donate blood regularly! ~Kevin on 16 Nov.
  

• Why does baking soda and water help relieve bee stings and other insect bites?
• Hmmm. . . baking soda is soothing for skin irritations, but I never stopped to consider why that is. I'm not going to look it up today, but in the meantime I'll mention that in Australia there are deadly jellyfish called "box jellyfish" or "sea wasps." They are very small so you wouldn't even notice if they were in the water, but a sting from one can be fatal. At beaches where these jellyfish sometimes are found they have vinegar available at first-aid stations. If you get stung by a jellyfish you are supposed to pour vinegar on the sting. It is possible that you have a bit of tentacle stuck to your arm or leg, and vinegarwill prevent any additional stinging cells (nematocysts) from firing. This certainly has to do with the change in pH. Baking soda is alkaline, not acidic, but the change in pH may be part of why it soothes. I am reminded of the time as a kid that I chased a chipmunk into a large patch of stinging nettle--and I was only wearing a pair of shorts! ~K
  

What happens when a person smokes a cigarette (nicotine-stimulant) and drinks alcohol (depressant) soon after?