The modern world can be quite toxic between the pesticides, GMOs, and chemical additives in the food, and heavy metals in the water and soil.
Our liver is the powerhouse that is designed to deal with this onslaught of toxins, but over time it can become over burdened. When this happens, it is called "total load". The body hits a wall where it can't deal with all of the toxins and symptoms start to appear.
For some people, the skin takes a hit. Our skin is the largest detoxification organ, and when eczema, rashes, and acne show up, it's a good indicator that the liver is working too hard.
For others food allergies become a major problem. Take GMO corn, it is used as an ingredient in a majority of processed foods. It goes by many names including maltodextrin, vegetable oil, cellulose, artifical flavors and colors, and acetic acid. It's also a staple of many factory farmed animal's diet. The point is that you end up eating a large amount of this altered corn, and then the liver and immune system then have to deal with it. Many people's sudden allergies to almonds, broccoli, or eggs (for example) is actually the body hitting that wall and not being able to handle substances that were once fine.
A few of the ways that you can reduce your toxic load are to eat whole unprocessed foods, use natural cleaning and beauty products, and drink filtered water. You can also try an elimination diet to figure out if corn, wheat, soy, or dairy could be the underlying cause of your health imbalances.