Causes

Pregnancy

Swollen feet have many causes, and are often one of the discomforts experienced during pregnancy. It may be unsettling for a pregnant woman to notice her feet swelling but there is no cause for worry, as swollen feet are very common at this time. This is because pregnancy puts a strain on the circulatory system. The uterus, which is growing in size, puts pressure on the vena cava, which is the vein that receives blood from the legs. Due to this pressure, the blood cannot flow upwards easily, and gets trapped in the lower limbs, forcing water down to your feet and ankles. This is not excessive fluid; it is simply concentrated in the feet instead of being distributed around the body. Thus, while a natural impulse would be to take diuretics (substances that flush water out of your body, like coffee), as you would in the case of water retention, these diuretics are not recommended for this condition, as they may cause dehydration, even if the swelling is indeed caused by excessive water retention. Pregnant women do tend to retain excessive water, which adds to the swelling. 

Similarly, your hands may swell up a little as well. But if you notice excessive swelling in the hands or face, you should consult a doctor, as this may be a symptom of pre-eclampsia. 
 

Journey

In addition to pregnancy, there are various other causes for swollen feet. If you have been on a long journey, an air flight or a bus ride, you may develop swollen feet due to the lack of movement. In fact, sitting anywhere for a prolonged period of time is definitely not good for circulation, and it is advisable to get up and walk around every once in a while. 
 

Health Conditions

Other causes include a condition formerly known as dropsy, where the heart cannot keep up with the pace of the blood being circulated back to it. Swelling is also caused due to malnutrition or kidney problems. Advanced age too can cause swelling, as ageing veins lose their ability to return blood to the heart as efficiently as they once did. 
 

Treatment

Cold water is very good, as it gives a boost to blood circulation. Keep your feet under running cold water for a while, and then raise them. Do this by lying next to a wall, and propping your feet up against it, at a 90 degree angle. Alternatively, try lying down on a mattress, and rest your feet on a raised surface like a chair. Stay in this position for at least ten to fifteen minutes. The swelling will reduce. 

You could also try wrapping your feet in a cold compress, and then raising them. 

Of course, you cannot spend the entire day sitting with your feet propped up, but you could spritz some cool water or cooling foot spray on your feet whenever possible. 

Even though swelling is caused due to pools of water in your feet, it is advisable to drink plenty of water. Yes, keeping your body well hydrated will reduce swelling. You could, however, avoid salty foods and snacks. 

At any time when you are sitting, either at work or at home, keep a footstool or any object that can serve as a footstool, and prop your legs up on it.  

In case of swelling due to ageing, it is best if you try and keep yourself as active as possible. Go for regular walks - this does wonders for blood circulation. While resting, keep your feet elevated, and while lying down, keep feet above the level of the heart for a short while everyday.