I define health as not just feeling well but being well. Many people feel okay but have underlying symptoms that later become more noticeable and prominent. Illness is any symptom that abnormal and harmful to you. With health there is many factors: physical, emotional and genetically. I learned this during physiology class at MSU, your health has many dimensions. Illness can exist without being notice, for example cancer and STDs.
I found infertility and interesting condition from the list. I consider it to not be an illness specifically because it does not really harm your body. Often it may be a symptom of an illness or a result from a procedure. This is not going to make your body any worse, it can often be undone or assisted to fertility. It is not a disease but more of a dysfunction like people born with an extra toe, they are not sick, something happened that was uncontrollable. Most illnesses can be controlled or slowed. All women reach a point in their lives where they become infertile.
I found sadness to also be interesting because it is a normal emotion that sometimes can be a symptom of illnesses. This is more of an emotional health problem because it does not harm you physically. Sadness often only lasts a short while, if it is longer than a month I would become concerned for my health. Sadness is a part of life for all individual but if the timing or time period gets a little off, one should pursue a second opinion from a doctor.
Some of these conditions could be tricky depending on what brought on the condition. Such as the two I listed. If a woman suddenly becomes infertile it could be a symptom of an illness. Same goes for sadness, If your sad because of an event such as a death or a rough path in life that normal. But if your sad randomly when you are normally content this could be a condition of an illness, such as Bipolar Disorder. I see how people could have different answers and find different ones more challenging.