Player status bars are the four bars that can be found on top of the inventory slots, and the fifth bar appears on top of said bars when the player is underwater. These indicate the status of the player's Health / Life, Hunger, Cold, Water and Oxygen. Players need to make sure to keep all five up at all times: when one of the other four bars are out, the player starts to lose health. If the player runs out of health, the player dies.
Life is basic. Players lose life upon player or mob attack, or by standing too close to a spike or campfire. Losing all your health results in death (unless if you have a dragon heart, or are wearing the Crown of the Angel). Players will regenerate 5% of the life bar every 10 seconds if all of the other bars (food, cold, water and oxygen) are above 35%. Bandages will help players regain life faster (increasing regeneration by 3x). However, if one or more of the other bars are not above 35%, a bandage has no effect.
Food bar will slowly decrease over time. Food can be obtained from hunting mobs, or by farming plants (berries and wheat), which replenishes some or all of the food bar upon consumption. The amount of food bar each type of food bar can restore is written on the food pages. Your food bar decreases by 3% every 5 seconds. This means without eating, the food bar goes from full to completely empty in exactly 2 minutes 50 seconds. Once drained, you take 10% damage every 5 seconds.
Cold bar will also decrease over time. (the name is actually inverse - when the cold bar is full the player is warm, when the cold bar is empty, the player is freezing.) During the day, the cold bar will gradually decrease for those without chapkas, or other cold resistant clothing (wearing a coat or cap and scarf will completely stop cold bar reduction during the day in the forest). At night, the cold bar will decrease very quickly, especially in the winter biome. In such occasions, players will be required to be near a fire in order to warm up from time to time. During night, the cold bars of players without chapkas equipped goes from full to empty in about 25 seconds. Once the cold bar is completely drained, you take 10% damage every 5 seconds.
Water bar shows how well the player is hydrated, and decreases slowly over time, at about the same rate as the food bar. Players can drink water by going into the water, standing on a bridge in a lake or the ocean, or by using a full water bottle. Your water bar decreases by 2% every 5 seconds. This means without drinking, the water bar goes from full to completely empty in exactly 4 minutes 10 seconds. Once drained, you take 10% damage every 5 seconds.
Oxygen bar is hidden at full status, and will stay full until the player goes into a lake or the ocean. It appears as a white bar on top of the four other bars. Swimming without diving suits causes the oxygen bar to rapidly drain by 25% every 5 seconds, i. e. 20 seconds to empty. It regenerates as soon as the player gets back onto land. Wear a diving mask or a diving suit to slow down the decreasing speed of this bar while swimming. When oxygen is completely drained, you take 20% damage every 5 seconds.